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How can I know the address of framebuffer of Xenfb #1

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LoveZJT opened this issue Apr 4, 2019 · 0 comments
Open

How can I know the address of framebuffer of Xenfb #1

LoveZJT opened this issue Apr 4, 2019 · 0 comments

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@LoveZJT
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LoveZJT commented Apr 4, 2019

I'm run my bare-mental examples on qemu and want to write the video. So I have to know the address of framebuffer of Xenfb. Where can I find it?
Thx

olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 16, 2019
Spotted by ASAN, during make check...

Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7f8e27262c48 in malloc (/lib64/libasan.so.5+0xeec48)
    xen-project#1 0x7f8e26a5f3c5 in g_malloc (/lib64/libglib-2.0.so.0+0x523c5)
    #2 0x555ab67078a8 in qstring_from_str /home/elmarco/src/qq/qobject/qstring.c:67
    #3 0x555ab67071e4 in qstring_new /home/elmarco/src/qq/qobject/qstring.c:24
    #4 0x555ab6713fbf in qstring_from_escaped_str /home/elmarco/src/qq/qobject/json-parser.c:144
    #5 0x555ab671738c in parse_literal /home/elmarco/src/qq/qobject/json-parser.c:506
    #6 0x555ab67179c3 in parse_value /home/elmarco/src/qq/qobject/json-parser.c:569
    #7 0x555ab6715123 in parse_pair /home/elmarco/src/qq/qobject/json-parser.c:306
    #8 0x555ab6715483 in parse_object /home/elmarco/src/qq/qobject/json-parser.c:357
    #9 0x555ab671798b in parse_value /home/elmarco/src/qq/qobject/json-parser.c:561
    #10 0x555ab6717a6b in json_parser_parse_err /home/elmarco/src/qq/qobject/json-parser.c:592
    #11 0x555ab4fd4dcf in handle_qmp_command /home/elmarco/src/qq/monitor.c:4257
    #12 0x555ab6712c4d in json_message_process_token /home/elmarco/src/qq/qobject/json-streamer.c:105
    #13 0x555ab67e01e2 in json_lexer_feed_char /home/elmarco/src/qq/qobject/json-lexer.c:323
    #14 0x555ab67e0af6 in json_lexer_feed /home/elmarco/src/qq/qobject/json-lexer.c:373
    #15 0x555ab6713010 in json_message_parser_feed /home/elmarco/src/qq/qobject/json-streamer.c:124
    #16 0x555ab4fd58ec in monitor_qmp_read /home/elmarco/src/qq/monitor.c:4337
    #17 0x555ab6559df2 in qemu_chr_be_write_impl /home/elmarco/src/qq/chardev/char.c:175
    #18 0x555ab6559e95 in qemu_chr_be_write /home/elmarco/src/qq/chardev/char.c:187
    #19 0x555ab6560127 in fd_chr_read /home/elmarco/src/qq/chardev/char-fd.c:66
    #20 0x555ab65d9c73 in qio_channel_fd_source_dispatch /home/elmarco/src/qq/io/channel-watch.c:84
    #21 0x7f8e26a598ac in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x4c8ac)

Signed-off-by: Marc-André Lureau <[email protected]>
Message-Id: <[email protected]>
[Screwed up in commit b273145]
Cc: [email protected]
Reviewed-by: Markus Armbruster <[email protected]>
Signed-off-by: Markus Armbruster <[email protected]>
(cherry picked from commit cb9ec42)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 16, 2019
Let start from the beginning:

Commit b9e413d (in 2.9)
"block: explicitly acquire aiocontext in aio callbacks that need it"
added pairs of aio_context_acquire/release to mirror_write_complete and
mirror_read_complete, when they were aio callbacks for blk_aio_* calls.

Then, commit 2e1990b (in 3.0) "block/mirror: Convert to coroutines"
dropped these blk_aio_* calls, than mirror_write_complete and
mirror_read_complete are not callbacks more, and don't need additional
aiocontext acquiring. Furthermore, mirror_read_complete calls
blk_co_pwritev inside these pair of aio_context_acquire/release, which
leads to the following dead-lock with mirror:

 (gdb) info thr
   Id   Target Id         Frame
   3    Thread (LWP 145412) "qemu-system-x86" syscall ()
   2    Thread (LWP 145416) "qemu-system-x86" __lll_lock_wait ()
 * 1    Thread (LWP 145411) "qemu-system-x86" __lll_lock_wait ()

 (gdb) bt
 #0  __lll_lock_wait ()
 xen-project#1  _L_lock_812 ()
 #2  __GI___pthread_mutex_lock
 #3  qemu_mutex_lock_impl (mutex=0x561032dce420 <qemu_global_mutex>,
     file=0x5610327d8654 "util/main-loop.c", line=236) at
     util/qemu-thread-posix.c:66
 #4  qemu_mutex_lock_iothread_impl
 #5  os_host_main_loop_wait (timeout=480116000) at util/main-loop.c:236
 #6  main_loop_wait (nonblocking=0) at util/main-loop.c:497
 #7  main_loop () at vl.c:1892
 #8  main

Printing contents of qemu_global_mutex, I see that "__owner = 145416",
so, thr1 is main loop, and now it wants BQL, which is owned by thr2.

 (gdb) thr 2
 (gdb) bt
 #0  __lll_lock_wait ()
 xen-project#1  _L_lock_870 ()
 #2  __GI___pthread_mutex_lock
 #3  qemu_mutex_lock_impl (mutex=0x561034d25dc0, ...
 #4  aio_context_acquire (ctx=0x561034d25d60)
 #5  dma_blk_cb
 #6  dma_blk_io
 #7  dma_blk_read
 #8  ide_dma_cb
 #9  bmdma_cmd_writeb
 #10 bmdma_write
 #11 memory_region_write_accessor
 #12 access_with_adjusted_size
 #15 flatview_write
 #16 address_space_write
 #17 address_space_rw
 #18 kvm_handle_io
 #19 kvm_cpu_exec
 #20 qemu_kvm_cpu_thread_fn
 #21 qemu_thread_start
 #22 start_thread
 #23 clone ()

Printing mutex in fr 2, I see "__owner = 145411", so thr2 wants aio
context mutex, which is owned by thr1. Classic dead-lock.

Then, let's check that aio context is hold by mirror coroutine: just
print coroutine stack of first tracked request in mirror job target:

 (gdb) [...]
 (gdb) qemu coroutine 0x561035dd0860
 #0  qemu_coroutine_switch
 xen-project#1  qemu_coroutine_yield
 #2  qemu_co_mutex_lock_slowpath
 #3  qemu_co_mutex_lock
 #4  qcow2_co_pwritev
 #5  bdrv_driver_pwritev
 #6  bdrv_aligned_pwritev
 #7  bdrv_co_pwritev
 #8  blk_co_pwritev
 #9  mirror_read_complete () at block/mirror.c:232
 #10 mirror_co_read () at block/mirror.c:370
 #11 coroutine_trampoline
 #12 __start_context

Yes it is mirror_read_complete calling blk_co_pwritev after acquiring
aio context.

Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Reviewed-by: Max Reitz <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>
(cherry picked from commit d12ade5)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 16, 2019
When using the 9P2000.u version of the protocol, the following shell
command line in the guest can cause QEMU to crash:

    while true; do rm -rf aa; mkdir -p a/b & touch a/b/c & mv a aa; done

With 9P2000.u, file renaming is handled by the WSTAT command. The
v9fs_wstat() function calls v9fs_complete_rename(), which calls
v9fs_fix_path() for every fid whose path is affected by the change.
The involved calls to v9fs_path_copy() may race with any other access
to the fid path performed by some worker thread, causing a crash like
shown below:

Thread 12 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8, path=0x0,
 flags=65536, mode=0) at hw/9pfs/9p-local.c:59
59          while (*path && fd != -1) {
(gdb) bt
#0  0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8,
 path=0x0, flags=65536, mode=0) at hw/9pfs/9p-local.c:59
xen-project#1  0x0000555555a25e0c in local_opendir_nofollow (fs_ctx=0x555557d958b8,
 path=0x0) at hw/9pfs/9p-local.c:92
#2  0x0000555555a261b8 in local_lstat (fs_ctx=0x555557d958b8,
 fs_path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/9p-local.c:185
#3  0x0000555555a2b367 in v9fs_co_lstat (pdu=0x555557d97498,
 path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/cofile.c:53
#4  0x0000555555a1e9e2 in v9fs_stat (opaque=0x555557d97498)
 at hw/9pfs/9p.c:1083
#5  0x0000555555e060a2 in coroutine_trampoline (i0=-669165424, i1=32767)
 at util/coroutine-ucontext.c:116
#6  0x00007fffef4f5600 in __start_context () at /lib64/libc.so.6
#7  0x0000000000000000 in  ()
(gdb)

The fix is to take the path write lock when calling v9fs_complete_rename(),
like in v9fs_rename().

Impact:  DoS triggered by unprivileged guest users.

Fixes: CVE-2018-19489
Cc: P J P <[email protected]>
Reported-by: zhibin hu <[email protected]>
Reviewed-by: Prasad J Pandit <[email protected]>
Signed-off-by: Greg Kurz <[email protected]>
(cherry picked from commit 1d20398)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 16, 2019
When using the 9P2000.u version of the protocol, the following shell
command line in the guest can cause QEMU to crash:

    while true; do rm -rf aa; mkdir -p a/b & touch a/b/c & mv a aa; done

With 9P2000.u, file renaming is handled by the WSTAT command. The
v9fs_wstat() function calls v9fs_complete_rename(), which calls
v9fs_fix_path() for every fid whose path is affected by the change.
The involved calls to v9fs_path_copy() may race with any other access
to the fid path performed by some worker thread, causing a crash like
shown below:

Thread 12 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8, path=0x0,
 flags=65536, mode=0) at hw/9pfs/9p-local.c:59
59          while (*path && fd != -1) {
(gdb) bt
#0  0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8,
 path=0x0, flags=65536, mode=0) at hw/9pfs/9p-local.c:59
xen-project#1  0x0000555555a25e0c in local_opendir_nofollow (fs_ctx=0x555557d958b8,
 path=0x0) at hw/9pfs/9p-local.c:92
#2  0x0000555555a261b8 in local_lstat (fs_ctx=0x555557d958b8,
 fs_path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/9p-local.c:185
#3  0x0000555555a2b367 in v9fs_co_lstat (pdu=0x555557d97498,
 path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/cofile.c:53
#4  0x0000555555a1e9e2 in v9fs_stat (opaque=0x555557d97498)
 at hw/9pfs/9p.c:1083
#5  0x0000555555e060a2 in coroutine_trampoline (i0=-669165424, i1=32767)
 at util/coroutine-ucontext.c:116
#6  0x00007fffef4f5600 in __start_context () at /lib64/libc.so.6
#7  0x0000000000000000 in  ()
(gdb)

The fix is to take the path write lock when calling v9fs_complete_rename(),
like in v9fs_rename().

Impact:  DoS triggered by unprivileged guest users.

Fixes: CVE-2018-19489
Cc: P J P <[email protected]>
Reported-by: zhibin hu <[email protected]>
Reviewed-by: Prasad J Pandit <[email protected]>
Signed-off-by: Greg Kurz <[email protected]>
(cherry picked from commit 1d20398)
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue May 8, 2019
Since OpenBSD 6.0 [1], W^X is enforced by default [2].
TCG requires WX access. Disable W^X if it is available.
This fixes:

  # lm32-softmmu/qemu-system-lm32
  Could not allocate dynamic translator buffer

  # sysctl kern.wxabort=1
  kern.wxabort: 0 -> 1
  # lm32-softmmu/qemu-system-lm32
  mmap: Not supported
  Abort trap (core dumped)
  # gdb -q lm32-softmmu/qemu-system-lm32 qemu-system-lm32.core
  (gdb) bt
  #0  0x000017e3c156c50a in _thread_sys___syscall () at {standard input}:5
  xen-project#1  0x000017e3c15e5d7a in *_libc_mmap (addr=Variable "addr" is not available.) at /usr/src/lib/libc/sys/mmap.c:47
  #2  0x000017e17d9abc8b in alloc_code_gen_buffer () at /usr/src/qemu/accel/tcg/translate-all.c:1064
  #3  0x000017e17d9abd04 in code_gen_alloc (tb_size=0) at /usr/src/qemu/accel/tcg/translate-all.c:1112
  #4  0x000017e17d9abe81 in tcg_exec_init (tb_size=0) at /usr/src/qemu/accel/tcg/translate-all.c:1149
  #5  0x000017e17d9897e9 in tcg_init (ms=0x17e45e456800) at /usr/src/qemu/accel/tcg/tcg-all.c:66
  #6  0x000017e17d9891b8 in accel_init_machine (acc=0x17e3c3f50800, ms=0x17e45e456800) at /usr/src/qemu/accel/accel.c:63
  #7  0x000017e17d989312 in configure_accelerator (ms=0x17e45e456800, progname=0x7f7fffff07b0 "lm32-softmmu/qemu-system-lm32") at /usr/src/qemu/accel/accel.c:111
  #8  0x000017e17d9d8616 in main (argc=1, argv=0x7f7fffff06b8, envp=0x7f7fffff06c8) at vl.c:4325

[1] https://www.openbsd.org/faq/upgrade60.html
[2] https://undeadly.org/cgi?action=article&sid=20160527203200

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue May 8, 2019
This fixes when configuring with --without-default-devices:

  $ qemu-system-mips64el -bios /dev/null -M fulong2e
  qemu-system-mips64el: Unknown device 'ati-vga' for bus 'PCI'
  Aborted (core dumped)

  (gdb) bt
  #0  0x00007ffff5a2753f in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
  xen-project#1  0x00007ffff5a11895 in __GI_abort () at abort.c:79
  #2  0x00005555558768d3 in qdev_create (bus=bus@entry=0x5555562664b0, name=name@entry=0x555555b24efb "ati-vga") at hw/core/qdev.c:131
  #3  0x00005555558d15e1 in pci_create_multifunction (bus=bus@entry=0x5555562664b0, devfn=devfn@entry=-1, multifunction=multifunction@entry=false, name=name@entry=0x555555b24efb "ati-vga") at hw/pci/pci.c:2104
  #4  0x00005555558d1a7a in pci_create (bus=bus@entry=0x5555562664b0, devfn=devfn@entry=-1, name=name@entry=0x555555b24efb "ati-vga") at hw/pci/pci.c:2121
  #5  0x0000555555763081 in mips_fulong2e_init (machine=<optimized out>) at hw/mips/mips_fulong2e.c:352
  #6  0x000055555587e23b in machine_run_board_init (machine=0x5555560b2000) at hw/core/machine.c:1030
  #7  0x00005555556cbea2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4463

And then:

  $ qemu-system-mips64el -bios /dev/null -M fulong2e
  qemu-system-mips64el: Unsupported NIC model: rtl8139

Fixes: 862b4a2 and 7c28b92
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue May 8, 2019
KVM has two bugs in the handling of MSR_IA32_ARCH_CAPABILITIES:

1) Linux commit commit 1eaafe91a0df ("kvm: x86: IA32_ARCH_CAPABILITIES
   is always supported") makes GET_SUPPORTED_CPUID return
   arch_capabilities even if running on SVM.  This makes "-cpu
   host,migratable=off" incorrectly expose arch_capabilities on CPUID on
   AMD hosts (where the MSR is not emulated by KVM).

2) KVM_GET_MSR_INDEX_LIST does not return MSR_IA32_ARCH_CAPABILITIES if
   the MSR is not supported by the host CPU.  This makes QEMU not
   initialize the MSR properly at kvm_put_msrs() on those hosts.

Work around both bugs on the QEMU side, by checking if the MSR
was returned by KVM_GET_MSR_INDEX_LIST before returning the
feature flag on kvm_arch_get_supported_cpuid().

This has the unfortunate side effect of making arch_capabilities
unavailable on hosts without hardware support for the MSR until bug #2
is fixed on KVM, but I can't see another way to work around bug xen-project#1
without that side effect.

Signed-off-by: Eduardo Habkost <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Eduardo Habkost <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jul 3, 2019
When using the 9P2000.u version of the protocol, the following shell
command line in the guest can cause QEMU to crash:

    while true; do rm -rf aa; mkdir -p a/b & touch a/b/c & mv a aa; done

With 9P2000.u, file renaming is handled by the WSTAT command. The
v9fs_wstat() function calls v9fs_complete_rename(), which calls
v9fs_fix_path() for every fid whose path is affected by the change.
The involved calls to v9fs_path_copy() may race with any other access
to the fid path performed by some worker thread, causing a crash like
shown below:

Thread 12 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8, path=0x0,
 flags=65536, mode=0) at hw/9pfs/9p-local.c:59
59          while (*path && fd != -1) {
(gdb) bt
#0  0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8,
 path=0x0, flags=65536, mode=0) at hw/9pfs/9p-local.c:59
xen-project#1  0x0000555555a25e0c in local_opendir_nofollow (fs_ctx=0x555557d958b8,
 path=0x0) at hw/9pfs/9p-local.c:92
#2  0x0000555555a261b8 in local_lstat (fs_ctx=0x555557d958b8,
 fs_path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/9p-local.c:185
#3  0x0000555555a2b367 in v9fs_co_lstat (pdu=0x555557d97498,
 path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/cofile.c:53
#4  0x0000555555a1e9e2 in v9fs_stat (opaque=0x555557d97498)
 at hw/9pfs/9p.c:1083
#5  0x0000555555e060a2 in coroutine_trampoline (i0=-669165424, i1=32767)
 at util/coroutine-ucontext.c:116
#6  0x00007fffef4f5600 in __start_context () at /lib64/libc.so.6
#7  0x0000000000000000 in  ()
(gdb)

The fix is to take the path write lock when calling v9fs_complete_rename(),
like in v9fs_rename().

Impact:  DoS triggered by unprivileged guest users.

Fixes: CVE-2018-19489
Cc: P J P <[email protected]>
Reported-by: zhibin hu <[email protected]>
Reviewed-by: Prasad J Pandit <[email protected]>
Signed-off-by: Greg Kurz <[email protected]>
(cherry picked from commit 1d20398)
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
When emulating irqchip in qemu, such as following command:

x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img
-machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor stdio

We will get a crash with following asan output:

(qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error: index 35 out of bounds for type 'int [24]'
=================================================================
==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00
WRITE of size 4 at 0x61b000003114 thread T4
    #0 0x5579e3c7a80e in ioapic_eoi_broadcast /home/test/qemu5/qemu/hw/intc/ioapic.c:266
    xen-project#1 0x5579e3c6f480 in apic_eoi /home/test/qemu5/qemu/hw/intc/apic.c:428
    #2 0x5579e3c720a7 in apic_mem_write /home/test/qemu5/qemu/hw/intc/apic.c:802
    #3 0x5579e3b1e31a in memory_region_write_accessor /home/test/qemu5/qemu/memory.c:503
    #4 0x5579e3b1e6a2 in access_with_adjusted_size /home/test/qemu5/qemu/memory.c:569
    #5 0x5579e3b28d77 in memory_region_dispatch_write /home/test/qemu5/qemu/memory.c:1497
    #6 0x5579e3a1b36b in flatview_write_continue /home/test/qemu5/qemu/exec.c:3323
    #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362
    #8 0x5579e3a1bcb1 in address_space_write /home/test/qemu5/qemu/exec.c:3452
    #9 0x5579e3a1bd03 in address_space_rw /home/test/qemu5/qemu/exec.c:3463
    #10 0x5579e3b8b979 in kvm_cpu_exec /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045
    #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn /home/test/qemu5/qemu/cpus.c:1287
    #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502
    #13 0x7fd0146376da in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)
    #14 0x7fd01436088e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x12188e

This is because in ioapic_eoi_broadcast function, we uses 'vector' to
index the 's->irq_eoi'. To fix this, we should uses the irq number.

Signed-off-by: Li Qiang <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Message-Id: <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
The test aarch64 kernel is in an array defined with
 unsigned char aarch64_kernel[] = { [...] }

which means it could be any size; currently it's quite small.
However we write it to a file using init_bootfile(), which
writes exactly 512 bytes to the file. This will break if
we ever end up with a kernel larger than that, and will
read garbage off the end of the array in the current setup
where the kernel is smaller.

Make init_bootfile() take an argument giving the length of
the data to write. This allows us to use it for all architectures
(previously s390 had a special-purpose init_bootfile_s390x
which hardcoded the file to write so it could write the
correct length). We assert that the x86 bootfile really is
exactly 512 bytes as it should be (and as we were previously
just assuming it was).

This was detected by the clang-7 asan:
==15607==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55a796f51d20 at pc 0x55a796b89c2f bp 0x7ffc58e89160 sp 0x7ffc58e88908
READ of size 512 at 0x55a796f51d20 thread T0
    #0 0x55a796b89c2e in fwrite (/home/petmay01/linaro/qemu-from-laptop/qemu/build/sanitizers/tests/migration-test+0xb0c2e)
    xen-project#1 0x55a796c46492 in init_bootfile /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:99:5
    #2 0x55a796c46492 in test_migrate_start /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:593
    #3 0x55a796c44101 in test_baddest /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:854:9
    #4 0x7f906ffd3cc9  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72cc9)
    #5 0x7f906ffd3bfa  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72bfa)
    #6 0x7f906ffd3bfa  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72bfa)
    #7 0x7f906ffd3ea1 in g_test_run_suite (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72ea1)
    #8 0x7f906ffd3ec0 in g_test_run (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72ec0)
    #9 0x55a796c43707 in main /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:1187:11
    #10 0x7f906e9abb96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
    #11 0x55a796b6c2d9 in _start (/home/petmay01/linaro/qemu-from-laptop/qemu/build/sanitizers/tests/migration-test+0x932d9)

Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
Reading the RX_DATA register when the RX_FIFO is empty triggers
an abort. This can be easily reproduced:

  $ qemu-system-arm -M emcraft-sf2 -monitor stdio -S
  QEMU 4.0.50 monitor - type 'help' for more information
  (qemu) x 0x40001010
  Aborted (core dumped)

  (gdb) bt
  xen-project#1  0x00007f035874f895 in abort () at /lib64/libc.so.6
  #2  0x00005628686591ff in fifo8_pop (fifo=0x56286a9a4c68) at util/fifo8.c:66
  #3  0x00005628683e0b8e in fifo32_pop (fifo=0x56286a9a4c68) at include/qemu/fifo32.h:137
  #4  0x00005628683e0efb in spi_read (opaque=0x56286a9a4850, addr=4, size=4) at hw/ssi/mss-spi.c:168
  #5  0x0000562867f96801 in memory_region_read_accessor (mr=0x56286a9a4b60, addr=16, value=0x7ffeecb0c5c8, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439
  #6  0x0000562867f96cdb in access_with_adjusted_size (addr=16, value=0x7ffeecb0c5c8, size=4, access_size_min=1, access_size_max=4, access_fn=0x562867f967c3 <memory_region_read_accessor>, mr=0x56286a9a4b60, attrs=...) at memory.c:569
  #7  0x0000562867f99940 in memory_region_dispatch_read1 (mr=0x56286a9a4b60, addr=16, pval=0x7ffeecb0c5c8, size=4, attrs=...) at memory.c:1420
  #8  0x0000562867f99a08 in memory_region_dispatch_read (mr=0x56286a9a4b60, addr=16, pval=0x7ffeecb0c5c8, size=4, attrs=...) at memory.c:1447
  #9  0x0000562867f38721 in flatview_read_continue (fv=0x56286aec6360, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, addr1=16, l=4, mr=0x56286a9a4b60) at exec.c:3385
  #10 0x0000562867f38874 in flatview_read (fv=0x56286aec6360, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4) at exec.c:3423
  #11 0x0000562867f388ea in address_space_read_full (as=0x56286aa3e890, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4) at exec.c:3436
  #12 0x0000562867f389c5 in address_space_rw (as=0x56286aa3e890, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, is_write=false) at exec.c:3466
  #13 0x0000562867f3bdd7 in cpu_memory_rw_debug (cpu=0x56286aa19d00, addr=1073745936, buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, is_write=0) at exec.c:3976
  #14 0x000056286811ed51 in memory_dump (mon=0x56286a8c32d0, count=1, format=120, wsize=4, addr=1073745936, is_physical=0) at monitor/misc.c:730
  #15 0x000056286811eff1 in hmp_memory_dump (mon=0x56286a8c32d0, qdict=0x56286b15c400) at monitor/misc.c:785
  #16 0x00005628684740ee in handle_hmp_command (mon=0x56286a8c32d0, cmdline=0x56286a8caeb2 "0x40001010") at monitor/hmp.c:1082

From the datasheet "Actel SmartFusion Microcontroller Subsystem
User's Guide" Rev.1, Table 13-3 "SPI Register Summary", this
register has a reset value of 0.

Check the FIFO is not empty before accessing it, else log an
error message.

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
In the previous commit we fixed a crash when the guest read a
register that pop from an empty FIFO.
By auditing the repository, we found another similar use with
an easy way to reproduce:

  $ qemu-system-aarch64 -M xlnx-zcu102 -monitor stdio -S
  QEMU 4.0.50 monitor - type 'help' for more information
  (qemu) xp/b 0xfd4a0134
  Aborted (core dumped)

  (gdb) bt
  #0  0x00007f6936dea57f in raise () at /lib64/libc.so.6
  xen-project#1  0x00007f6936dd4895 in abort () at /lib64/libc.so.6
  #2  0x0000561ad32975ec in xlnx_dp_aux_pop_rx_fifo (s=0x7f692babee70) at hw/display/xlnx_dp.c:431
  #3  0x0000561ad3297dc0 in xlnx_dp_read (opaque=0x7f692babee70, offset=77, size=4) at hw/display/xlnx_dp.c:667
  #4  0x0000561ad321b896 in memory_region_read_accessor (mr=0x7f692babf620, addr=308, value=0x7ffe05c1db88, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439
  #5  0x0000561ad321bd70 in access_with_adjusted_size (addr=308, value=0x7ffe05c1db88, size=1, access_size_min=4, access_size_max=4, access_fn=0x561ad321b858 <memory_region_read_accessor>, mr=0x7f692babf620, attrs=...) at memory.c:569
  #6  0x0000561ad321e9d5 in memory_region_dispatch_read1 (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1420
  #7  0x0000561ad321ea9d in memory_region_dispatch_read (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1447
  #8  0x0000561ad31bd742 in flatview_read_continue (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1, addr1=308, l=1, mr=0x7f692babf620) at exec.c:3385
  #9  0x0000561ad31bd895 in flatview_read (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3423
  #10 0x0000561ad31bd90b in address_space_read_full (as=0x561ad5bb3020, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3436
  #11 0x0000561ad33b1c42 in address_space_read (len=1, buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", attrs=..., addr=4249485620, as=0x561ad5bb3020) at include/exec/memory.h:2131
  #12 0x0000561ad33b1c42 in memory_dump (mon=0x561ad59c4530, count=1, format=120, wsize=1, addr=4249485620, is_physical=1) at monitor/misc.c:723
  #13 0x0000561ad33b1fc1 in hmp_physical_memory_dump (mon=0x561ad59c4530, qdict=0x561ad6c6fd00) at monitor/misc.c:795
  #14 0x0000561ad37b4a9f in handle_hmp_command (mon=0x561ad59c4530, cmdline=0x561ad59d0f22 "/b 0x00000000fd4a0134") at monitor/hmp.c:1082

Fix by checking the FIFO is not empty before popping from it.

The datasheet is not clear about the reset value of this register,
we choose to return '0'.

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
When creating the admin queue in nvme_init() the variable that
holds the number of queues created is modified before actual
queue creation. This is a problem because if creating the queue
fails then the variable is left in inconsistent state. This was
actually observed when I tried to hotplug a nvme disk. The
control got to nvme_file_open() which called nvme_init() which
failed and thus nvme_close() was called which in turn called
nvme_free_queue_pair() with queue being NULL. This lead to an
instant crash:

  #0  0x000055d9507ec211 in nvme_free_queue_pair (bs=0x55d952ddb880, q=0x0) at block/nvme.c:164
  xen-project#1  0x000055d9507ee180 in nvme_close (bs=0x55d952ddb880) at block/nvme.c:729
  #2  0x000055d9507ee3d5 in nvme_file_open (bs=0x55d952ddb880, options=0x55d952bb1410, flags=147456, errp=0x7ffd8e19e200) at block/nvme.c:781
  #3  0x000055d9507629f3 in bdrv_open_driver (bs=0x55d952ddb880, drv=0x55d95109c1e0 <bdrv_nvme>, node_name=0x0, options=0x55d952bb1410, open_flags=147456, errp=0x7ffd8e19e310) at block.c:1291
  #4  0x000055d9507633d6 in bdrv_open_common (bs=0x55d952ddb880, file=0x0, options=0x55d952bb1410, errp=0x7ffd8e19e310) at block.c:1551
  #5  0x000055d950766881 in bdrv_open_inherit (filename=0x0, reference=0x0, options=0x55d952bb1410, flags=32768, parent=0x55d9538ce420, child_role=0x55d950eaade0 <child_file>, errp=0x7ffd8e19e510) at block.c:3063
  #6  0x000055d950765ae4 in bdrv_open_child_bs (filename=0x0, options=0x55d9541cdff0, bdref_key=0x55d950af33aa "file", parent=0x55d9538ce420, child_role=0x55d950eaade0 <child_file>, allow_none=true, errp=0x7ffd8e19e510) at block.c:2712
  #7  0x000055d950766633 in bdrv_open_inherit (filename=0x0, reference=0x0, options=0x55d9541cdff0, flags=0, parent=0x0, child_role=0x0, errp=0x7ffd8e19e908) at block.c:3011
  #8  0x000055d950766dba in bdrv_open (filename=0x0, reference=0x0, options=0x55d953d00390, flags=0, errp=0x7ffd8e19e908) at block.c:3156
  #9  0x000055d9507cb635 in blk_new_open (filename=0x0, reference=0x0, options=0x55d953d00390, flags=0, errp=0x7ffd8e19e908) at block/block-backend.c:389
  #10 0x000055d950465ec5 in blockdev_init (file=0x0, bs_opts=0x55d953d00390, errp=0x7ffd8e19e908) at blockdev.c:602

Signed-off-by: Michal Privoznik <[email protected]>
Message-id: 927aae40b617ba7d4b6c7ffe74e6d7a2595f8e86.1562770546.git.mprivozn@redhat.com
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Maxim Levitsky <[email protected]>
Signed-off-by: Max Reitz <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
commit a6f230c move blockbackend back to main AioContext on unplug. It set the AioContext of
SCSIDevice to the main AioContex, but s->ctx is still the iothread AioContex(if the scsi controller
is configure with iothread). So if there are having in-flight requests during unplug, a failing assertion
happend. The bt is below:
(gdb) bt
#0  0x0000ffff86aacbd0 in raise () from /lib64/libc.so.6
xen-project#1  0x0000ffff86aadf7c in abort () from /lib64/libc.so.6
#2  0x0000ffff86aa6124 in __assert_fail_base () from /lib64/libc.so.6
#3  0x0000ffff86aa61a4 in __assert_fail () from /lib64/libc.so.6
#4  0x0000000000529118 in virtio_scsi_ctx_check (d=<optimized out>, s=<optimized out>, s=<optimized out>) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:246
#5  0x0000000000529ec4 in virtio_scsi_handle_cmd_req_prepare (s=0x2779ec00, req=0xffff740397d0) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:559
#6  0x000000000052a228 in virtio_scsi_handle_cmd_vq (s=0x2779ec00, vq=0xffff7c6d7110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:603
#7  0x000000000052afa8 in virtio_scsi_data_plane_handle_cmd (vdev=<optimized out>, vq=0xffff7c6d7110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi-dataplane.c:59
#8  0x000000000054d94c in virtio_queue_host_notifier_aio_poll (opaque=<optimized out>) at /home/qemu-4.0.0/hw/virtio/virtio.c:2452

assert(blk_get_aio_context(d->conf.blk) == s->ctx) failed.

To avoid assertion failed,  moving the "if" after qdev_simple_device_unplug_cb.

In addition, to avoid another qemu crash below, add aio_disable_external before
qdev_simple_device_unplug_cb, which disable the further processing of external clients
when doing qdev_simple_device_unplug_cb.
(gdb) bt
#0  scsi_req_unref (req=0xffff6802c6f0) at hw/scsi/scsi-bus.c:1283
xen-project#1  0x00000000005294a4 in virtio_scsi_handle_cmd_req_submit (req=<optimized out>,
    s=<optimized out>) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:589
#2  0x000000000052a2a8 in virtio_scsi_handle_cmd_vq (s=s@entry=0x9c90e90,
    vq=vq@entry=0xffff7c05f110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:625
#3  0x000000000052afd8 in virtio_scsi_data_plane_handle_cmd (vdev=<optimized out>,
    vq=0xffff7c05f110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi-dataplane.c:60
#4  0x000000000054d97c in virtio_queue_host_notifier_aio_poll (opaque=<optimized out>)
    at /home/qemu-4.0.0/hw/virtio/virtio.c:2447
#5  0x00000000009b204c in run_poll_handlers_once (ctx=ctx@entry=0x6efea40,
    timeout=timeout@entry=0xffff7d7f7308) at util/aio-posix.c:521
#6  0x00000000009b2b64 in run_poll_handlers (ctx=ctx@entry=0x6efea40,
    max_ns=max_ns@entry=4000, timeout=timeout@entry=0xffff7d7f7308) at util/aio-posix.c:559
#7  0x00000000009b2ca0 in try_poll_mode (ctx=ctx@entry=0x6efea40, timeout=0xffff7d7f7308,
    timeout@entry=0xffff7d7f7348) at util/aio-posix.c:594
#8  0x00000000009b31b8 in aio_poll (ctx=0x6efea40, blocking=blocking@entry=true)
    at util/aio-posix.c:636
#9  0x00000000006973cc in iothread_run (opaque=0x6ebd800) at iothread.c:75
#10 0x00000000009b592c in qemu_thread_start (args=0x6efef60) at util/qemu-thread-posix.c:502
#11 0x0000ffff8057f8bc in start_thread () from /lib64/libpthread.so.0
#12 0x0000ffff804e5f8c in thread_start () from /lib64/libc.so.6
(gdb) p bus
$1 = (SCSIBus *) 0x0

Signed-off-by: Zhengui li <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 19, 2019
Commit 4812f26 tried to fix rollback path of xics_kvm_connect() but
it isn't enough. If we fail to create the KVM device, the guest fails
to boot later on with:

[    0.010817] pci 0000:00:00.0: Adding to iommu group 0
[    0.010863] irq: unknown-1 didn't like hwirq-0x1200 to VIRQ17 mapping (rc=-22)
[    0.010923] pci 0000:00:01.0: Adding to iommu group 0
[    0.010968] irq: unknown-1 didn't like hwirq-0x1201 to VIRQ17 mapping (rc=-22)
[    0.011543] EEH: No capable adapters found
[    0.011597] irq: unknown-1 didn't like hwirq-0x1000 to VIRQ17 mapping (rc=-22)
[    0.011651] audit: type=2000 audit(1563977526.000:1): state=initialized audit_enabled=0 res=1
[    0.011703] ------------[ cut here ]------------
[    0.011729] event-sources: Unable to allocate interrupt number for /event-sources/epow-events
[    0.011776] WARNING: CPU: 0 PID: 1 at arch/powerpc/platforms/pseries/event_sources.c:34 request_event_sources_irqs+0xbc/0x150
[    0.011828] Modules linked in:
[    0.011850] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.1.17-300.fc30.ppc64le xen-project#1
[    0.011886] NIP:  c0000000000d4fac LR: c0000000000d4fa8 CTR: c0000000018f0000
[    0.011923] REGS: c00000001e4c38d0 TRAP: 0700   Not tainted  (5.1.17-300.fc30.ppc64le)
[    0.011966] MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 28000284  XER: 20040000
[    0.012012] CFAR: c00000000011b42c IRQMASK: 0
[    0.012012] GPR00: c0000000000d4fa8 c00000001e4c3b60 c0000000015fc400 0000000000000051
[    0.012012] GPR04: 0000000000000001 0000000000000000 0000000000000081 772d6576656e7473
[    0.012012] GPR08: 000000001edf0000 c0000000014d4830 c0000000014d4830 6e6576652f20726f
[    0.012012] GPR12: 0000000000000000 c0000000018f0000 c000000000010bf0 0000000000000000
[    0.012012] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[    0.012012] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[    0.012012] GPR24: 0000000000000000 0000000000000000 c000000000ebbf00 c0000000000d5570
[    0.012012] GPR28: c000000000ebc008 c00000001fff8248 0000000000000000 0000000000000000
[    0.012372] NIP [c0000000000d4fac] request_event_sources_irqs+0xbc/0x150
[    0.012409] LR [c0000000000d4fa8] request_event_sources_irqs+0xb8/0x150
[    0.012445] Call Trace:
[    0.012462] [c00000001e4c3b60] [c0000000000d4fa8] request_event_sources_irqs+0xb8/0x150 (unreliable)
[    0.012513] [c00000001e4c3bf0] [c000000001042848] __machine_initcall_pseries_init_ras_IRQ+0xc8/0xf8
[    0.012563] [c00000001e4c3c20] [c000000000010810] do_one_initcall+0x60/0x254
[    0.012611] [c00000001e4c3cf0] [c000000001024538] kernel_init_freeable+0x35c/0x444
[    0.012655] [c00000001e4c3db0] [c000000000010c14] kernel_init+0x2c/0x148
[    0.012693] [c00000001e4c3e20] [c00000000000bdc4] ret_from_kernel_thread+0x5c/0x78
[    0.012736] Instruction dump:
[    0.012759] 38a00000 7c7f1b78 7f64db78 2c1f0000 2fbf0000 78630020 4180002c 409effa8
[    0.012805] 7fa4eb78 7f43d378 48046421 60000000 <0fe00000> 3bde0001 2c1e0010 7fde07b4
[    0.012851] ---[ end trace aa5785707323fad3 ]---

This happens because QEMU fell back on XICS emulation but didn't unregister
the RTAS calls from KVM. The emulated RTAS calls are hence never called and
the KVM ones return an error to the guest since the KVM device is absent.

The sanity checks in xics_kvm_disconnect() are abusive since we're freeing
the KVM device. Simply drop them.

Fixes: 4812f26 "xics/kvm: Add proper rollback to xics_kvm_init()"
Signed-off-by: Greg Kurz <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Cédric Le Goater <[email protected]>
Signed-off-by: David Gibson <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 15, 2020
Currently offloads disabled by guest via the VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET
command are not preserved on VM migration.
Instead all offloads reported by guest features (via VIRTIO_PCI_GUEST_FEATURES)
get enabled.
What happens is: first the VirtIONet::curr_guest_offloads gets restored and offloads
are getting set correctly:

 #0  qemu_set_offload (nc=0x555556a11400, csum=1, tso4=0, tso6=0, ecn=0, ufo=0) at net/net.c:474
 xen-project#1  virtio_net_apply_guest_offloads (n=0x555557701ca0) at hw/net/virtio-net.c:720
 #2  virtio_net_post_load_device (opaque=0x555557701ca0, version_id=11) at hw/net/virtio-net.c:2334
 #3  vmstate_load_state (f=0x5555569dc010, vmsd=0x555556577c80 <vmstate_virtio_net_device>, opaque=0x555557701ca0, version_id=11)
     at migration/vmstate.c:168
 #4  virtio_load (vdev=0x555557701ca0, f=0x5555569dc010, version_id=11) at hw/virtio/virtio.c:2197
 #5  virtio_device_get (f=0x5555569dc010, opaque=0x555557701ca0, size=0, field=0x55555668cd00 <__compound_literal.5>) at hw/virtio/virtio.c:2036
 #6  vmstate_load_state (f=0x5555569dc010, vmsd=0x555556577ce0 <vmstate_virtio_net>, opaque=0x555557701ca0, version_id=11) at migration/vmstate.c:143
 #7  vmstate_load (f=0x5555569dc010, se=0x5555578189e0) at migration/savevm.c:829
 #8  qemu_loadvm_section_start_full (f=0x5555569dc010, mis=0x5555569eee20) at migration/savevm.c:2211
 #9  qemu_loadvm_state_main (f=0x5555569dc010, mis=0x5555569eee20) at migration/savevm.c:2395
 #10 qemu_loadvm_state (f=0x5555569dc010) at migration/savevm.c:2467
 #11 process_incoming_migration_co (opaque=0x0) at migration/migration.c:449

However later on the features are getting restored, and offloads get reset to
everything supported by features:

 #0  qemu_set_offload (nc=0x555556a11400, csum=1, tso4=1, tso6=1, ecn=0, ufo=0) at net/net.c:474
 xen-project#1  virtio_net_apply_guest_offloads (n=0x555557701ca0) at hw/net/virtio-net.c:720
 #2  virtio_net_set_features (vdev=0x555557701ca0, features=5104441767) at hw/net/virtio-net.c:773
 #3  virtio_set_features_nocheck (vdev=0x555557701ca0, val=5104441767) at hw/virtio/virtio.c:2052
 #4  virtio_load (vdev=0x555557701ca0, f=0x5555569dc010, version_id=11) at hw/virtio/virtio.c:2220
 #5  virtio_device_get (f=0x5555569dc010, opaque=0x555557701ca0, size=0, field=0x55555668cd00 <__compound_literal.5>) at hw/virtio/virtio.c:2036
 #6  vmstate_load_state (f=0x5555569dc010, vmsd=0x555556577ce0 <vmstate_virtio_net>, opaque=0x555557701ca0, version_id=11) at migration/vmstate.c:143
 #7  vmstate_load (f=0x5555569dc010, se=0x5555578189e0) at migration/savevm.c:829
 #8  qemu_loadvm_section_start_full (f=0x5555569dc010, mis=0x5555569eee20) at migration/savevm.c:2211
 #9  qemu_loadvm_state_main (f=0x5555569dc010, mis=0x5555569eee20) at migration/savevm.c:2395
 #10 qemu_loadvm_state (f=0x5555569dc010) at migration/savevm.c:2467
 #11 process_incoming_migration_co (opaque=0x0) at migration/migration.c:449

Fix this by preserving the state in saved_guest_offloads field and
pushing out offload initialization to the new post load hook.

Cc: [email protected]
Signed-off-by: Mikhail Sennikovsky <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
(cherry picked from commit 7788c3f)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 15, 2020
When 'system_reset' is called, the main loop clear the memory
region cache before the BH has a chance to execute. Later when
the deferred function is called, some assumptions that were
made when scheduling them are no longer true when they actually
execute.

This is what happens using a virtio-blk device (fresh RHEL7.8 install):

 $ (sleep 12.3; echo system_reset; sleep 12.3; echo system_reset; sleep 1; echo q) \
   | qemu-system-x86_64 -m 4G -smp 8 -boot menu=on \
     -device virtio-blk-pci,id=image1,drive=drive_image1 \
     -drive file=/var/lib/libvirt/images/rhel78.qcow2,if=none,id=drive_image1,format=qcow2,cache=none \
     -device virtio-net-pci,netdev=net0,id=nic0,mac=52:54:00:c4:e7:84 \
     -netdev tap,id=net0,script=/bin/true,downscript=/bin/true,vhost=on \
     -monitor stdio -serial null -nographic
  (qemu) system_reset
  (qemu) system_reset
  (qemu) qemu-system-x86_64: hw/virtio/virtio.c:225: vring_get_region_caches: Assertion `caches != NULL' failed.
  Aborted

  (gdb) bt
  Thread 1 (Thread 0x7f109c17b680 (LWP 10939)):
  #0  0x00005604083296d1 in vring_get_region_caches (vq=0x56040a24bdd0) at hw/virtio/virtio.c:227
  xen-project#1  0x000056040832972b in vring_avail_flags (vq=0x56040a24bdd0) at hw/virtio/virtio.c:235
  #2  0x000056040832d13d in virtio_should_notify (vdev=0x56040a240630, vq=0x56040a24bdd0) at hw/virtio/virtio.c:1648
  #3  0x000056040832d1f8 in virtio_notify_irqfd (vdev=0x56040a240630, vq=0x56040a24bdd0) at hw/virtio/virtio.c:1662
  #4  0x00005604082d213d in notify_guest_bh (opaque=0x56040a243ec0) at hw/block/dataplane/virtio-blk.c:75
  #5  0x000056040883dc35 in aio_bh_call (bh=0x56040a243f10) at util/async.c:90
  #6  0x000056040883dccd in aio_bh_poll (ctx=0x560409161980) at util/async.c:118
  #7  0x0000560408842af7 in aio_dispatch (ctx=0x560409161980) at util/aio-posix.c:460
  #8  0x000056040883e068 in aio_ctx_dispatch (source=0x560409161980, callback=0x0, user_data=0x0) at util/async.c:261
  #9  0x00007f10a8fca06d in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
  #10 0x0000560408841445 in glib_pollfds_poll () at util/main-loop.c:215
  #11 0x00005604088414bf in os_host_main_loop_wait (timeout=0) at util/main-loop.c:238
  #12 0x00005604088415c4 in main_loop_wait (nonblocking=0) at util/main-loop.c:514
  #13 0x0000560408416b1e in main_loop () at vl.c:1923
  #14 0x000056040841e0e8 in main (argc=20, argv=0x7ffc2c3f9c58, envp=0x7ffc2c3f9d00) at vl.c:4578

Fix this by cancelling the BH when the virtio dataplane is stopped.

[This is version of the patch was modified as discussed with Philippe on
the mailing list thread.
--Stefan]

Reported-by: Yihuang Yu <[email protected]>
Suggested-by: Stefan Hajnoczi <[email protected]>
Fixes: https://bugs.launchpad.net/qemu/+bug/1839428
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Stefan Hajnoczi <[email protected]>
(cherry picked from commit ebb6ff2)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 15, 2020
The 'blockdev-create' QMP command was introduced as experimental
feature in commit b0292b8, using the assert() debug call.
It got promoted to 'stable' command in 3fb588a, but the
assert call was not removed.

Some block drivers are optional, and bdrv_find_format() might
return a NULL value, triggering the assertion.

Stable code is not expected to abort, so return an error instead.

This is easily reproducible when libnfs is not installed:

  ./configure
  [...]
  module support    no
  Block whitelist (rw)
  Block whitelist (ro)
  libiscsi support  yes
  libnfs support    no
  [...]

Start QEMU:

  $ qemu-system-x86_64 -S -qmp unix:/tmp/qemu.qmp,server,nowait

Send the 'blockdev-create' with the 'nfs' driver:

  $ ( cat << 'EOF'
  {'execute': 'qmp_capabilities'}
  {'execute': 'blockdev-create', 'arguments': {'job-id': 'x', 'options': {'size': 0, 'driver': 'nfs', 'location': {'path': '/', 'server': {'host': '::1', 'type': 'inet'}}}}, 'id': 'x'}
  EOF
  ) | socat STDIO UNIX:/tmp/qemu.qmp
  {"QMP": {"version": {"qemu": {"micro": 50, "minor": 1, "major": 4}, "package": "v4.1.0-733-g89ea03a7dc"}, "capabilities": ["oob"]}}
  {"return": {}}

QEMU crashes:

  $ gdb qemu-system-x86_64 core
  Program received signal SIGSEGV, Segmentation fault.
  (gdb) bt
  #0  0x00007ffff510957f in raise () at /lib64/libc.so.6
  xen-project#1  0x00007ffff50f3895 in abort () at /lib64/libc.so.6
  #2  0x00007ffff50f3769 in _nl_load_domain.cold.0 () at /lib64/libc.so.6
  #3  0x00007ffff5101a26 in .annobin_assert.c_end () at /lib64/libc.so.6
  #4  0x0000555555d7e1f1 in qmp_blockdev_create (job_id=0x555556baee40 "x", options=0x555557666610, errp=0x7fffffffc770) at block/create.c:69
  #5  0x0000555555c96b52 in qmp_marshal_blockdev_create (args=0x7fffdc003830, ret=0x7fffffffc7f8, errp=0x7fffffffc7f0) at qapi/qapi-commands-block-core.c:1314
  #6  0x0000555555deb0a0 in do_qmp_dispatch (cmds=0x55555645de70 <qmp_commands>, request=0x7fffdc005c70, allow_oob=false, errp=0x7fffffffc898) at qapi/qmp-dispatch.c:131
  #7  0x0000555555deb2a1 in qmp_dispatch (cmds=0x55555645de70 <qmp_commands>, request=0x7fffdc005c70, allow_oob=false) at qapi/qmp-dispatch.c:174

With this patch applied, QEMU returns a QMP error:

  {'execute': 'blockdev-create', 'arguments': {'job-id': 'x', 'options': {'size': 0, 'driver': 'nfs', 'location': {'path': '/', 'server': {'host': '::1', 'type': 'inet'}}}}, 'id': 'x'}
  {"id": "x", "error": {"class": "GenericError", "desc": "Block driver 'nfs' not found or not supported"}}

Cc: [email protected]
Reported-by: Xu Tian <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: John Snow <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>
(cherry picked from commit d90d5ca)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
'crypto_opts' forgot to free in qcow2_close(), this patch fix the bellow leak stack:

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f0edd81f970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
    xen-project#1 0x7f0edc6d149d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
    #2 0x55d7eaede63d in qobject_input_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qobject-input-visitor.c:295
    #3 0x55d7eaed78b8 in visit_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qapi-visit-core.c:49
    #4 0x55d7eaf5140b in visit_type_QCryptoBlockOpenOptions qapi/qapi-visit-crypto.c:290
    #5 0x55d7eae43af3 in block_crypto_open_opts_init /mnt/sdb/qemu-new/qemu_test/qemu/block/crypto.c:163
    #6 0x55d7eacd2924 in qcow2_update_options_prepare /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1148
    #7 0x55d7eacd33f7 in qcow2_update_options /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1232
    #8 0x55d7eacd9680 in qcow2_do_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1512
    #9 0x55d7eacdc55e in qcow2_open_entry /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1792
    #10 0x55d7eacdc8fe in qcow2_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1819
    #11 0x55d7eac3742d in bdrv_open_driver /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1317
    #12 0x55d7eac3e990 in bdrv_open_common /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1575
    #13 0x55d7eac4442c in bdrv_open_inherit /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3126
    #14 0x55d7eac45c3f in bdrv_open /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3219
    #15 0x55d7ead8e8a4 in blk_new_open /mnt/sdb/qemu-new/qemu_test/qemu/block/block-backend.c:397
    #16 0x55d7eacde74c in qcow2_co_create /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3534
    #17 0x55d7eacdfa6d in qcow2_co_create_opts /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3668
    #18 0x55d7eac1c678 in bdrv_create_co_entry /mnt/sdb/qemu-new/qemu_test/qemu/block.c:485
    #19 0x55d7eb0024d2 in coroutine_trampoline /mnt/sdb/qemu-new/qemu_test/qemu/util/coroutine-ucontext.c:115

Reported-by: Euler Robot <[email protected]>
Signed-off-by: Pan Nengyuan <[email protected]>
Reviewed-by: Max Reitz <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Max Reitz <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
'type/id' forgot to free in qmp_object_add, this patch fix that.

The leak stack:
Direct leak of 84 byte(s) in 6 object(s) allocated from:
    #0 0x7fe2a5ebf768 in __interceptor_malloc (/lib64/libasan.so.5+0xef768)
    xen-project#1 0x7fe2a5044445 in g_malloc (/lib64/libglib-2.0.so.0+0x52445)
    #2 0x7fe2a505dd92 in g_strdup (/lib64/libglib-2.0.so.0+0x6bd92)
    #3 0x56344954e692 in qmp_object_add /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qmp-cmds.c:258
    #4 0x563449960f5a in do_qmp_dispatch /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qmp-dispatch.c:132
    #5 0x563449960f5a in qmp_dispatch /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qmp-dispatch.c:175
    #6 0x563449498a30 in monitor_qmp_dispatch /mnt/sdb/qemu-new/qemu_test/qemu/monitor/qmp.c:145
    #7 0x56344949a64f in monitor_qmp_bh_dispatcher /mnt/sdb/qemu-new/qemu_test/qemu/monitor/qmp.c:234
    #8 0x563449a92a3a in aio_bh_call /mnt/sdb/qemu-new/qemu_test/qemu/util/async.c:136

Direct leak of 54 byte(s) in 6 object(s) allocated from:
    #0 0x7fe2a5ebf768 in __interceptor_malloc (/lib64/libasan.so.5+0xef768)
    xen-project#1 0x7fe2a5044445 in g_malloc (/lib64/libglib-2.0.so.0+0x52445)
    #2 0x7fe2a505dd92 in g_strdup (/lib64/libglib-2.0.so.0+0x6bd92)
    #3 0x56344954e6c4 in qmp_object_add /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qmp-cmds.c:267
    #4 0x563449960f5a in do_qmp_dispatch /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qmp-dispatch.c:132
    #5 0x563449960f5a in qmp_dispatch /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qmp-dispatch.c:175
    #6 0x563449498a30 in monitor_qmp_dispatch /mnt/sdb/qemu-new/qemu_test/qemu/monitor/qmp.c:145
    #7 0x56344949a64f in monitor_qmp_bh_dispatcher /mnt/sdb/qemu-new/qemu_test/qemu/monitor/qmp.c:234
    #8 0x563449a92a3a in aio_bh_call /mnt/sdb/qemu-new/qemu_test/qemu/util/async.c:136

Fixes: 5f07c4d
Reported-by: Euler Robot <[email protected]>
Signed-off-by: Pan Nengyuan <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Daniel P. Berrangé <[email protected]>
Acked-by: Igor Mammedov <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
Previously, the signal handler would be byte swapped if the target and
host CPU used different endianness. This would cause a SIGSEGV when
attempting to translate the opcode pointed to by the swapped address.

 Thread 1 "qemu-ppc64" received signal SIGSEGV, Segmentation fault.
 0x00000000600a9257 in ldl_he_p (ptr=0x4c2c061000000000) at qemu/include/qemu/bswap.h:351
 351        __builtin_memcpy(&r, ptr, sizeof(r));

 #0  0x00000000600a9257 in ldl_he_p (ptr=0x4c2c061000000000) at qemu/include/qemu/bswap.h:351
 xen-project#1  0x00000000600a92fe in ldl_be_p (ptr=0x4c2c061000000000) at qemu/include/qemu/bswap.h:449
 #2  0x00000000600c0790 in translator_ldl_swap at qemu/include/exec/translator.h:201
 #3  0x000000006011c1ab in ppc_tr_translate_insn at qemu/target/ppc/translate.c:7856
 #4  0x000000006005ae70 in translator_loop at qemu/accel/tcg/translator.c:102

The signal handler will be byte swapped as a result of the __get_user()
call in sigaction() if it is necessary, no additional swap is required.

Signed-off-by: Vincent Fazio <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: David Gibson <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
There is a use-after-free possible: bdrv_unref_child() leaves
bs->backing freed but not NULL. bdrv_attach_child may produce nested
polling loop due to drain, than access of freed pointer is possible.

I've produced the following crash on 30 iotest with modified code. It
does not reproduce on master, but still seems possible:

    #0  __strcmp_avx2 () at /lib64/libc.so.6
    xen-project#1  bdrv_backing_overridden (bs=0x55c9d3cc2060) at block.c:6350
    #2  bdrv_refresh_filename (bs=0x55c9d3cc2060) at block.c:6404
    #3  bdrv_backing_attach (c=0x55c9d48e5520) at block.c:1063
    #4  bdrv_replace_child_noperm
        (child=child@entry=0x55c9d48e5520,
        new_bs=new_bs@entry=0x55c9d3cc2060) at block.c:2290
    #5  bdrv_replace_child
        (child=child@entry=0x55c9d48e5520,
        new_bs=new_bs@entry=0x55c9d3cc2060) at block.c:2320
    #6  bdrv_root_attach_child
        (child_bs=child_bs@entry=0x55c9d3cc2060,
        child_name=child_name@entry=0x55c9d241d478 "backing",
        child_role=child_role@entry=0x55c9d26ecee0 <child_backing>,
        ctx=<optimized out>, perm=<optimized out>, shared_perm=21,
        opaque=0x55c9d3c5a3d0, errp=0x7ffd117108e0) at block.c:2424
    #7  bdrv_attach_child
        (parent_bs=parent_bs@entry=0x55c9d3c5a3d0,
        child_bs=child_bs@entry=0x55c9d3cc2060,
        child_name=child_name@entry=0x55c9d241d478 "backing",
        child_role=child_role@entry=0x55c9d26ecee0 <child_backing>,
        errp=errp@entry=0x7ffd117108e0) at block.c:5876
    #8  in bdrv_set_backing_hd
        (bs=bs@entry=0x55c9d3c5a3d0,
        backing_hd=backing_hd@entry=0x55c9d3cc2060,
        errp=errp@entry=0x7ffd117108e0)
        at block.c:2576
    #9  stream_prepare (job=0x55c9d49d84a0) at block/stream.c:150
    #10 job_prepare (job=0x55c9d49d84a0) at job.c:761
    #11 job_txn_apply (txn=<optimized out>, fn=<optimized out>) at
        job.c:145
    #12 job_do_finalize (job=0x55c9d49d84a0) at job.c:778
    #13 job_completed_txn_success (job=0x55c9d49d84a0) at job.c:832
    #14 job_completed (job=0x55c9d49d84a0) at job.c:845
    #15 job_completed (job=0x55c9d49d84a0) at job.c:836
    #16 job_exit (opaque=0x55c9d49d84a0) at job.c:864
    #17 aio_bh_call (bh=0x55c9d471a160) at util/async.c:117
    #18 aio_bh_poll (ctx=ctx@entry=0x55c9d3c46720) at util/async.c:117
    #19 aio_poll (ctx=ctx@entry=0x55c9d3c46720,
        blocking=blocking@entry=true)
        at util/aio-posix.c:728
    #20 bdrv_parent_drained_begin_single (poll=true, c=0x55c9d3d558f0)
        at block/io.c:121
    #21 bdrv_parent_drained_begin_single (c=c@entry=0x55c9d3d558f0,
        poll=poll@entry=true)
        at block/io.c:114
    #22 bdrv_replace_child_noperm
        (child=child@entry=0x55c9d3d558f0,
        new_bs=new_bs@entry=0x55c9d3d27300) at block.c:2258
    #23 bdrv_replace_child
        (child=child@entry=0x55c9d3d558f0,
        new_bs=new_bs@entry=0x55c9d3d27300) at block.c:2320
    #24 bdrv_root_attach_child
        (child_bs=child_bs@entry=0x55c9d3d27300,
        child_name=child_name@entry=0x55c9d241d478 "backing",
        child_role=child_role@entry=0x55c9d26ecee0 <child_backing>,
        ctx=<optimized out>, perm=<optimized out>, shared_perm=21,
        opaque=0x55c9d3cc2060, errp=0x7ffd11710c60) at block.c:2424
    #25 bdrv_attach_child
        (parent_bs=parent_bs@entry=0x55c9d3cc2060,
        child_bs=child_bs@entry=0x55c9d3d27300,
        child_name=child_name@entry=0x55c9d241d478 "backing",
        child_role=child_role@entry=0x55c9d26ecee0 <child_backing>,
        errp=errp@entry=0x7ffd11710c60) at block.c:5876
    #26 bdrv_set_backing_hd
        (bs=bs@entry=0x55c9d3cc2060,
        backing_hd=backing_hd@entry=0x55c9d3d27300,
        errp=errp@entry=0x7ffd11710c60)
        at block.c:2576
    #27 stream_prepare (job=0x55c9d495ead0) at block/stream.c:150
    ...

Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: John Snow <[email protected]>
Signed-off-by: Max Reitz <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
We neglect to free port->bh on the error paths.  Fix that.
Reproducer:
    {'execute': 'device_add', 'arguments': {'id': 'virtio_serial_pci0', 'driver': 'virtio-serial-pci', 'bus': 'pci.0', 'addr': '0x5'}, 'id': 'yVkZcGgV'}
    {'execute': 'device_add', 'arguments': {'id': 'port1', 'driver': 'virtserialport', 'name': 'port1', 'chardev': 'channel1', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': '3dXdUgJA'}
    {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': 'qLzcCkob'}
    {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 2}, 'id': 'qLzcCkob'}

The leak stack:
Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7f04a8008ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8)
    xen-project#1 0x7f04a73cf1d5 in g_malloc (/lib64/libglib-2.0.so.0+0x531d5)
    #2 0x56273eaee484 in aio_bh_new /mnt/sdb/backup/qemu/util/async.c:125
    #3 0x56273eafe9a8 in qemu_bh_new /mnt/sdb/backup/qemu/util/main-loop.c:532
    #4 0x56273d52e62e in virtser_port_device_realize /mnt/sdb/backup/qemu/hw/char/virtio-serial-bus.c:946
    #5 0x56273dcc5040 in device_set_realized /mnt/sdb/backup/qemu/hw/core/qdev.c:891
    #6 0x56273e5ebbce in property_set_bool /mnt/sdb/backup/qemu/qom/object.c:2238
    #7 0x56273e5e5a9c in object_property_set /mnt/sdb/backup/qemu/qom/object.c:1324
    #8 0x56273e5ef5f8 in object_property_set_qobject /mnt/sdb/backup/qemu/qom/qom-qobject.c:26
    #9 0x56273e5e5e6a in object_property_set_bool /mnt/sdb/backup/qemu/qom/object.c:1390
    #10 0x56273daa40de in qdev_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:680
    #11 0x56273daa53e9 in qmp_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:805

Fixes: 199646d
Reported-by: Euler Robot <[email protected]>
Signed-off-by: Pan Nengyuan <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
virtio_vqs forgot to free on the error path in realize(). Fix that.

The asan stack:
Direct leak of 14336 byte(s) in 1 object(s) allocated from:
    #0 0x7f58b93fd970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
    xen-project#1 0x7f58b858249d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
    #2 0x5562cc627f49 in virtio_add_queue /mnt/sdb/qemu/hw/virtio/virtio.c:2413
    #3 0x5562cc4b524a in virtio_blk_device_realize /mnt/sdb/qemu/hw/block/virtio-blk.c:1202
    #4 0x5562cc613050 in virtio_device_realize /mnt/sdb/qemu/hw/virtio/virtio.c:3615
    #5 0x5562ccb7a568 in device_set_realized /mnt/sdb/qemu/hw/core/qdev.c:891
    #6 0x5562cd39cd45 in property_set_bool /mnt/sdb/qemu/qom/object.c:2238

Reported-by: Euler Robot <[email protected]>
Signed-off-by: Pan Nengyuan <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
The tulip networking card emulation has an OOB issue in
'tulip_copy_tx_buffers' when the guest provide malformed descriptor.
This test will trigger a ASAN heap overflow crash. To trigger this
issue we can construct the data as following:

1. construct a 'tulip_descriptor'. Its control is set to
'0x7ff | 0x7ff << 11', this will make the 'tulip_copy_tx_buffers's
'len1' and 'len2' to 0x7ff(2047). So 'len1+len2' will overflow
'TULIPState's 'tx_frame' field. This descriptor's 'buf_addr1' and
'buf_addr2' should set to a guest address.

2. write this descriptor to tulip device's CSR4 register. This will
set the 'TULIPState's 'current_tx_desc' field.

3. write 'CSR6_ST' to tulip device's CSR6 register. This will trigger
'tulip_xmit_list_update' and finally calls 'tulip_copy_tx_buffers'.

Following shows the backtrack of crash:

==31781==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x628000007cd0 at pc 0x7fe03c5a077a bp 0x7fff05b46770 sp 0x7fff05b45f18
WRITE of size 2047 at 0x628000007cd0 thread T0
    #0 0x7fe03c5a0779  (/usr/lib/x86_64-linux-gnu/libasan.so.4+0x79779)
    xen-project#1 0x5575fb6daa6a in flatview_read_continue /home/test/qemu/exec.c:3194
    #2 0x5575fb6daccb in flatview_read /home/test/qemu/exec.c:3227
    #3 0x5575fb6dae66 in address_space_read_full /home/test/qemu/exec.c:3240
    #4 0x5575fb6db0cb in address_space_rw /home/test/qemu/exec.c:3268
    #5 0x5575fbdfd460 in dma_memory_rw_relaxed /home/test/qemu/include/sysemu/dma.h:87
    #6 0x5575fbdfd4b5 in dma_memory_rw /home/test/qemu/include/sysemu/dma.h:110
    #7 0x5575fbdfd866 in pci_dma_rw /home/test/qemu/include/hw/pci/pci.h:787
    #8 0x5575fbdfd8a3 in pci_dma_read /home/test/qemu/include/hw/pci/pci.h:794
    #9 0x5575fbe02761 in tulip_copy_tx_buffers hw/net/tulip.c:585
    #10 0x5575fbe0366b in tulip_xmit_list_update hw/net/tulip.c:678
    #11 0x5575fbe04073 in tulip_write hw/net/tulip.c:783

Signed-off-by: Li Qiang <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
Since commit 8c6b035 ("util/async:
make bh_aio_poll() O(1)"), migration-test reveals a leak:

QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64
tests/qtest/migration-test  -p /x86_64/migration/postcopy/recovery
tests/qtest/libqtest.c:140: kill_qemu() tried to terminate QEMU
process but encountered exit status 1 (expected 0)

=================================================================
==2082571==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7f25971dfc58 in __interceptor_malloc (/lib64/libasan.so.5+0x10dc58)
    xen-project#1 0x7f2596d08358 in g_malloc (/lib64/libglib-2.0.so.0+0x57358)
    #2 0x560970d006f8 in qemu_bh_new /home/elmarco/src/qemu/util/main-loop.c:532
    #3 0x5609704afa02 in migrate_fd_connect
/home/elmarco/src/qemu/migration/migration.c:3407
    #4 0x5609704b6b6f in migration_channel_connect
/home/elmarco/src/qemu/migration/channel.c:92
    #5 0x5609704b2bfb in socket_outgoing_migration
/home/elmarco/src/qemu/migration/socket.c:108
    #6 0x560970b9bd6c in qio_task_complete /home/elmarco/src/qemu/io/task.c:196
    #7 0x560970b9aa97 in qio_task_thread_result
/home/elmarco/src/qemu/io/task.c:111
    #8 0x7f2596cfee3a  (/lib64/libglib-2.0.so.0+0x4de3a)

Signed-off-by: Marc-André Lureau <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Juan Quintela <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
Direct leak of 4120 byte(s) in 1 object(s) allocated from:
    #0 0x7fa114931887 in __interceptor_calloc (/lib64/libasan.so.6+0xb0887)
    xen-project#1 0x7fa1144ad8f0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x588f0)
    #2 0x561e3c9c8897 in qmp_object_add /home/elmarco/src/qemu/qom/qom-qmp-cmds.c:291
    #3 0x561e3cf48736 in qmp_dispatch /home/elmarco/src/qemu/qapi/qmp-dispatch.c:155
    #4 0x561e3c8efb36 in monitor_qmp_dispatch /home/elmarco/src/qemu/monitor/qmp.c:145
    #5 0x561e3c8f09ed in monitor_qmp_bh_dispatcher /home/elmarco/src/qemu/monitor/qmp.c:234
    #6 0x561e3d08c993 in aio_bh_call /home/elmarco/src/qemu/util/async.c:136
    #7 0x561e3d08d0a5 in aio_bh_poll /home/elmarco/src/qemu/util/async.c:164
    #8 0x561e3d0a535a in aio_dispatch /home/elmarco/src/qemu/util/aio-posix.c:380
    #9 0x561e3d08e3ca in aio_ctx_dispatch /home/elmarco/src/qemu/util/async.c:298
    #10 0x7fa1144a776e in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x5276e)

Signed-off-by: Marc-André Lureau <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Apr 29, 2020
There is an overflow, the source 'datain.data[2]' is 100 bytes,
 but the 'ss' is 252 bytes.This may cause a security issue because
 we can access a lot of unrelated memory data.

The len for sbp copy data should take the minimum of mx_sb_len and
 sb_len_wr, not the maximum.

If we use iscsi device for VM backend storage, ASAN show stack:

READ of size 252 at 0xfffd149dcfc4 thread T0
    #0 0xaaad433d0d34 in __asan_memcpy (aarch64-softmmu/qemu-system-aarch64+0x2cb0d34)
    xen-project#1 0xaaad45f9d6d0 in iscsi_aio_ioctl_cb /qemu/block/iscsi.c:996:9
    #2 0xfffd1af0e2dc  (/usr/lib64/iscsi/libiscsi.so.8+0xe2dc)
    #3 0xfffd1af0d174  (/usr/lib64/iscsi/libiscsi.so.8+0xd174)
    #4 0xfffd1af19fac  (/usr/lib64/iscsi/libiscsi.so.8+0x19fac)
    #5 0xaaad45f9acc8 in iscsi_process_read /qemu/block/iscsi.c:403:5
    #6 0xaaad4623733c in aio_dispatch_handler /qemu/util/aio-posix.c:467:9
    #7 0xaaad4622f350 in aio_dispatch_handlers /qemu/util/aio-posix.c:510:20
    #8 0xaaad4622f350 in aio_dispatch /qemu/util/aio-posix.c:520
    #9 0xaaad46215944 in aio_ctx_dispatch /qemu/util/async.c:298:5
    #10 0xfffd1bed12f4 in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x512f4)
    #11 0xaaad46227de0 in glib_pollfds_poll /qemu/util/main-loop.c:219:9
    #12 0xaaad46227de0 in os_host_main_loop_wait /qemu/util/main-loop.c:242
    #13 0xaaad46227de0 in main_loop_wait /qemu/util/main-loop.c:518
    #14 0xaaad43d9d60c in qemu_main_loop /qemu/softmmu/vl.c:1662:9
    #15 0xaaad4607a5b0 in main /qemu/softmmu/main.c:49:5
    #16 0xfffd1a460b9c in __libc_start_main (/lib64/libc.so.6+0x20b9c)
    #17 0xaaad43320740 in _start (aarch64-softmmu/qemu-system-aarch64+0x2c00740)

0xfffd149dcfc4 is located 0 bytes to the right of 100-byte region [0xfffd149dcf60,0xfffd149dcfc4)
allocated by thread T0 here:
    #0 0xaaad433d1e70 in __interceptor_malloc (aarch64-softmmu/qemu-system-aarch64+0x2cb1e70)
    xen-project#1 0xfffd1af0e254  (/usr/lib64/iscsi/libiscsi.so.8+0xe254)
    #2 0xfffd1af0d174  (/usr/lib64/iscsi/libiscsi.so.8+0xd174)
    #3 0xfffd1af19fac  (/usr/lib64/iscsi/libiscsi.so.8+0x19fac)
    #4 0xaaad45f9acc8 in iscsi_process_read /qemu/block/iscsi.c:403:5
    #5 0xaaad4623733c in aio_dispatch_handler /qemu/util/aio-posix.c:467:9
    #6 0xaaad4622f350 in aio_dispatch_handlers /qemu/util/aio-posix.c:510:20
    #7 0xaaad4622f350 in aio_dispatch /qemu/util/aio-posix.c:520
    #8 0xaaad46215944 in aio_ctx_dispatch /qemu/util/async.c:298:5
    #9 0xfffd1bed12f4 in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x512f4)
    #10 0xaaad46227de0 in glib_pollfds_poll /qemu/util/main-loop.c:219:9
    #11 0xaaad46227de0 in os_host_main_loop_wait /qemu/util/main-loop.c:242
    #12 0xaaad46227de0 in main_loop_wait /qemu/util/main-loop.c:518
    #13 0xaaad43d9d60c in qemu_main_loop /qemu/softmmu/vl.c:1662:9
    #14 0xaaad4607a5b0 in main /qemu/softmmu/main.c:49:5
    #15 0xfffd1a460b9c in __libc_start_main (/lib64/libc.so.6+0x20b9c)
    #16 0xaaad43320740 in _start (aarch64-softmmu/qemu-system-aarch64+0x2c00740)

Reported-by: Euler Robot <[email protected]>
Signed-off-by: Chen Qun <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
Message-id: [email protected]
Reviewed-by: Daniel P. Berrangé <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jun 15, 2020
When using the 9P2000.u version of the protocol, the following shell
command line in the guest can cause QEMU to crash:

    while true; do rm -rf aa; mkdir -p a/b & touch a/b/c & mv a aa; done

With 9P2000.u, file renaming is handled by the WSTAT command. The
v9fs_wstat() function calls v9fs_complete_rename(), which calls
v9fs_fix_path() for every fid whose path is affected by the change.
The involved calls to v9fs_path_copy() may race with any other access
to the fid path performed by some worker thread, causing a crash like
shown below:

Thread 12 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8, path=0x0,
 flags=65536, mode=0) at hw/9pfs/9p-local.c:59
59          while (*path && fd != -1) {
(gdb) bt
#0  0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8,
 path=0x0, flags=65536, mode=0) at hw/9pfs/9p-local.c:59
xen-project#1  0x0000555555a25e0c in local_opendir_nofollow (fs_ctx=0x555557d958b8,
 path=0x0) at hw/9pfs/9p-local.c:92
#2  0x0000555555a261b8 in local_lstat (fs_ctx=0x555557d958b8,
 fs_path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/9p-local.c:185
#3  0x0000555555a2b367 in v9fs_co_lstat (pdu=0x555557d97498,
 path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/cofile.c:53
#4  0x0000555555a1e9e2 in v9fs_stat (opaque=0x555557d97498)
 at hw/9pfs/9p.c:1083
#5  0x0000555555e060a2 in coroutine_trampoline (i0=-669165424, i1=32767)
 at util/coroutine-ucontext.c:116
#6  0x00007fffef4f5600 in __start_context () at /lib64/libc.so.6
#7  0x0000000000000000 in  ()
(gdb)

The fix is to take the path write lock when calling v9fs_complete_rename(),
like in v9fs_rename().

Impact:  DoS triggered by unprivileged guest users.

Fixes: CVE-2018-19489
Cc: P J P <[email protected]>
Reported-by: zhibin hu <[email protected]>
Reviewed-by: Prasad J Pandit <[email protected]>
Signed-off-by: Greg Kurz <[email protected]>
(cherry picked from commit 1d20398)
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 30, 2020
When adding the generic PCA955xClass in commit 736132e, we
forgot to set the class_size field. Fill it now to avoid:

  (gdb) run -machine mcimx6ul-evk -m 128M -display none -serial stdio -kernel ./OS.elf
  Starting program: ../../qemu/qemu/arm-softmmu/qemu-system-arm -machine mcimx6ul-evk -m 128M -display none -serial stdio -kernel ./OS.elf
  double free or corruption (!prev)
  Thread 1 "qemu-system-arm" received signal SIGABRT, Aborted.
  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
  (gdb) where
  #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
  xen-project#1  0x00007ffff75d8859 in __GI_abort () at abort.c:79
  #2  0x00007ffff76433ee in __libc_message
      (action=action@entry=do_abort, fmt=fmt@entry=0x7ffff776d285 "%s\n")
      at ../sysdeps/posix/libc_fatal.c:155
  #3  0x00007ffff764b47c in malloc_printerr
      (str=str@entry=0x7ffff776f690 "double free or corruption (!prev)")
      at malloc.c:5347
  #4  0x00007ffff764d12c in _int_free
      (av=0x7ffff779eb80 <main_arena>, p=0x5555567a3990, have_lock=<optimized out>) at malloc.c:4317
  #5  0x0000555555c906c3 in type_initialize_interface
      (ti=ti@entry=0x5555565b8f40, interface_type=0x555556597ad0, parent_type=0x55555662ca10) at qom/object.c:259
  #6  0x0000555555c902da in type_initialize (ti=ti@entry=0x5555565b8f40)
      at qom/object.c:323
  #7  0x0000555555c90d20 in type_initialize (ti=0x5555565b8f40)
      at qom/object.c:1028

  $ valgrind --track-origins=yes qemu-system-arm -M mcimx6ul-evk -m 128M -display none -serial stdio -kernel ./OS.elf
  ==77479== Memcheck, a memory error detector
  ==77479== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
  ==77479== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
  ==77479== Command: qemu-system-arm -M mcimx6ul-evk -m 128M -display none -serial stdio -kernel ./OS.elf
  ==77479==
  ==77479== Invalid write of size 2
  ==77479==    at 0x6D8322: pca9552_class_init (pca9552.c:424)
  ==77479==    by 0x844D1F: type_initialize (object.c:1029)
  ==77479==    by 0x844D1F: object_class_foreach_tramp (object.c:1016)
  ==77479==    by 0x4AE1057: g_hash_table_foreach (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.6400.2)
  ==77479==    by 0x8453A4: object_class_foreach (object.c:1038)
  ==77479==    by 0x8453A4: object_class_get_list (object.c:1095)
  ==77479==    by 0x556194: select_machine (vl.c:2416)
  ==77479==    by 0x556194: qemu_init (vl.c:3828)
  ==77479==    by 0x40AF9C: main (main.c:48)
  ==77479==  Address 0x583f108 is 0 bytes after a block of size 200 alloc'd
  ==77479==    at 0x483DD99: calloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==77479==    by 0x4AF8D30: g_malloc0 (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.6400.2)
  ==77479==    by 0x844258: type_initialize.part.0 (object.c:306)
  ==77479==    by 0x844D1F: type_initialize (object.c:1029)
  ==77479==    by 0x844D1F: object_class_foreach_tramp (object.c:1016)
  ==77479==    by 0x4AE1057: g_hash_table_foreach (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.6400.2)
  ==77479==    by 0x8453A4: object_class_foreach (object.c:1038)
  ==77479==    by 0x8453A4: object_class_get_list (object.c:1095)
  ==77479==    by 0x556194: select_machine (vl.c:2416)
  ==77479==    by 0x556194: qemu_init (vl.c:3828)
  ==77479==    by 0x40AF9C: main (main.c:48)

Fixes: 736132e ("hw/misc/pca9552: Add generic PCA955xClass")
Reported-by: Jean-Christophe DUBOIS <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Jean-Christophe DUBOIS <[email protected]>
Message-id: [email protected]
Reviewed-by: Peter Maydell <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Sep 1, 2021
When building the Pegasos2 machine stand-alone we get:

  $ qemu-system-ppc -M pegasos2 -bios pegasos2.rom
  ERROR:qom/object.c:714:object_new_with_type: assertion failed: (type != NULL)
  Bail out! ERROR:qom/object.c:714:object_new_with_type: assertion failed: (type != NULL)

Looking at the backtraces:

  Thread 1 "qemu-system-ppc" received signal SIGABRT, Aborted.
  (gdb) bt
  #0  0x00007ffff53877d5 in raise () at /lib64/libc.so.6
  xen-project#1  0x00007ffff5370895 in abort () at /lib64/libc.so.6
  #2  0x00007ffff6dc4b6c in g_assertion_message_expr.cold () at /lib64/libglib-2.0.so.0
  #3  0x00007ffff6e229ff in g_assertion_message_expr () at /lib64/libglib-2.0.so.0
  #4  0x0000555555a0c8f4 in object_new_with_type (type=0x0) at qom/object.c:714
  #5  0x0000555555a0c9d5 in object_new (typename=0x555555c7afe4 "isa-pit") at qom/object.c:747
  #6  0x0000555555a053b8 in qdev_new (name=0x555555c7afe4 "isa-pit") at hw/core/qdev.c:153
  #7  0x00005555557cdd05 in isa_new (name=0x555555c7afe4 "isa-pit") at hw/isa/isa-bus.c:160
  #8  0x00005555557cf518 in i8254_pit_init (bus=0x55555603d140, base=64, isa_irq=0, alt_irq=0x0) at include/hw/timer/i8254.h:54
  #9  0x00005555557d12f9 in vt8231_realize (d=0x5555563d9770, errp=0x7fffffffcc28) at hw/isa/vt82c686.c:704

  (gdb) bt
  #0  0x00007ffff54bd7d5 in raise () at /lib64/libc.so.6
  xen-project#1  0x00007ffff54a6895 in abort () at /lib64/libc.so.6
  #2  0x00005555558f7796 in object_new (typename=0x555555ad4889 "isa-parallel") at qom/object.c:749
  #3  object_new (typename=type0x555555ad4889 "isa-parallel") at qom/object.c:743
  #4  0x00005555558f0d46 in qdev_new (name=0x555555ad4889 "isa-parallel") at hw/core/qdev.c:153
  #5  0x000055555576b669 in isa_new (name=0x555555ad4889 "isa-parallel") at hw/isa/isa-bus.c:160
  #6  0x000055555576bbe8 in isa_superio_realize (dev=0x555555f15910, errp=<optimized out>) at hw/isa/isa-superio.c:54
  #7  0x000055555576d5ed in via_superio_realize (d=0x555555f15910, errp=0x7fffffffcb30) at hw/isa/vt82c686.c:292
  #8  0x00005555558f12c1 in device_set_realized (obj=<optimized out>, ...) at hw/core/qdev.c:761
  #9  0x00005555558f5066 in property_set_bool (obj=0x555555f15910, ..., errp=0x7fffffffcbb0) at qom/object.c:2262
  #10 0x00005555558f7f38 in object_property_set (obj=0x555555f15910, name=0x555555b1b1e3 "realized", ...) at qom/object.c:1407
  #11 0x00005555558fb2d0 in object_property_set_qobject (obj=0x555555f15910, name=0x555555b1b1e3 "realized", ...) at qom/qom-qobject.c:28
  #12 0x00005555558f8525 in object_property_set_bool (obj=0x555555f15910, name=0x555555b1b1e3 "realized", ...) at qom/object.c:1477
  #13 0x00005555558f18ee in qdev_realize (dev=0x555555f15910, bus=0x55555602a610, errp=<optimized out>) at hw/core/qdev.c:389
  #14 0x00005555558f197f in qdev_realize_and_unref (dev=0x555555f15910, bus=0x55555602a610, errp=<optimized out>) at hw/core/qdev.c:396
  #15 0x000055555576b709 in isa_realize_and_unref (errp=<optimized out>, bus=0x55555602a610, dev=0x555555f15910) at hw/isa/isa-bus.c:179
  #16 isa_create_simple (bus=0x55555602a610, name=0x555555adc33b "vt8231-superio") at hw/isa/isa-bus.c:173
  #17 0x000055555576d9b7 in vt8231_realize (d=0x555556186a50, errp=<optimized out>) at hw/isa/vt82c686.c:706

The "isa-pit" type (TYPE_I8254) and "isa-parallel" are missing. Add them.

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: BALATON Zoltan <[email protected]>
Reviewed-by: Bin Meng <[email protected]>
Message-Id: <[email protected]>
[PMD: Added "isa-parallel" later]
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jan 12, 2022
Both qemu and qemu-img use writeback cache mode by default, which is
already documented in qemu(1). qemu-nbd uses writethrough cache mode by
default, and the default cache mode is not documented.

According to the qemu-nbd(8):

   --cache=CACHE
          The  cache  mode  to be used with the file.  See the
          documentation of the emulator's -drive cache=... option for
          allowed values.

qemu(1) says:

    The default mode is cache=writeback.

So users have no reason to assume that qemu-nbd is using writethough
cache mode. The only hint is the painfully slow writing when using the
defaults.

Looking in git history, it seems that qemu used writethrough in the past
to support broken guests that did not flush data properly, or could not
flush due to limitations in qemu. But qemu-nbd clients can use
NBD_CMD_FLUSH to flush data, so using writethrough does not help anyone.

Change the default cache mode to writback, and document the default and
available values properly in the online help and manual.

With this change converting image via qemu-nbd is 3.5 times faster.

    $ qemu-img create dst.img 50g
    $ qemu-nbd -t -f raw -k /tmp/nbd.sock dst.img

Before this change:

    $ hyperfine -r3 "./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock"
    Benchmark xen-project#1: ./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock
      Time (mean ± σ):     83.639 s ±  5.970 s    [User: 2.733 s, System: 6.112 s]
      Range (min … max):   76.749 s … 87.245 s    3 runs

After this change:

    $ hyperfine -r3 "./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock"
    Benchmark xen-project#1: ./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock
      Time (mean ± σ):     23.522 s ±  0.433 s    [User: 2.083 s, System: 5.475 s]
      Range (min … max):   23.234 s … 24.019 s    3 runs

Users can avoid the issue by using --cache=writeback[1] but the defaults
should give good performance for the common use case.

[1] https://bugzilla.redhat.com/1990656

Signed-off-by: Nir Soffer <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
CC: [email protected]
Signed-off-by: Eric Blake <[email protected]>
(cherry picked from commit 0961525)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jan 12, 2022
PCI resource reserve capability should use LE format as all other PCI
things. If we don't then seabios won't boot:

=== PCI new allocation pass xen-project#1 ===
PCI: check devices
PCI: QEMU resource reserve cap: size 10000000000000 type io
PCI: secondary bus 1 size 10000000000000 type io
PCI: secondary bus 1 size 00200000 type mem
PCI: secondary bus 1 size 00200000 type prefmem
=== PCI new allocation pass #2 ===
PCI: out of I/O address space

This became more important since we started reserving IO by default,
previously no one noticed.

Fixes: e2a6290 ("hw/pcie-root-port: Fix hotplug for PCI devices requiring IO")
Cc: [email protected]
Fixes: 226263f ("hw/pci: add QEMU-specific PCI capability to the Generic PCI Express Root Port")
Cc: [email protected]
Fixes: 6755e61 ("hw/pci: add PCI resource reserve capability to legacy PCI bridge")
Cc: [email protected]
Tested-by: Thomas Huth <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
(cherry picked from commit 0e464f7)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jan 12, 2022
Without the previous commit, when running 'make check-qtest-i386'
with QEMU configured with '--enable-sanitizers' we get:

  AddressSanitizer:DEADLYSIGNAL
  =================================================================
  ==287878==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000344
  ==287878==The signal is caused by a WRITE memory access.
  ==287878==Hint: address points to the zero page.
      #0 0x564b2e5bac27 in blk_inc_in_flight block/block-backend.c:1346:5
      xen-project#1 0x564b2e5bb228 in blk_pwritev_part block/block-backend.c:1317:5
      #2 0x564b2e5bcd57 in blk_pwrite block/block-backend.c:1498:11
      #3 0x564b2ca1cdd3 in fdctrl_write_data hw/block/fdc.c:2221:17
      #4 0x564b2ca1b2f7 in fdctrl_write hw/block/fdc.c:829:9
      #5 0x564b2dc49503 in portio_write softmmu/ioport.c:201:9

Add the reproducer for CVE-2021-20196.

Suggested-by: Alexander Bulekov <[email protected]>
Reviewed-by: Darren Kenny <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
Signed-off-by: John Snow <[email protected]>
(cherry picked from commit cc20926)
Signed-off-by: Michael Roth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jun 17, 2022
In commit 00f05c0 we gave the TYPE_XLNX_CSU_DMA object its
own class struct, but forgot to update the TypeInfo::class_size
accordingly.  This meant that not enough memory was allocated for the
class struct, and the initialization of xcdc->read in the class init
function wrote off the end of the memory. Add the missing line.

Found by running 'check-qtest-aarch64' with a clang
address-sanitizer build, which complains:

==2542634==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61000000ab00 at pc 0x559a20aebc29 bp 0x7fff97df74d0 sp 0x7fff97df74c8
WRITE of size 8 at 0x61000000ab00 thread T0
    #0 0x559a20aebc28 in xlnx_csu_dma_class_init /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../hw/dma/xlnx_csu_dma.c:722:16
    xen-project#1 0x559a21bf297c in type_initialize /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../qom/object.c:365:9
    #2 0x559a21bf3442 in object_class_foreach_tramp /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../qom/object.c:1070:5
    #3 0x7f09bcb641b7 in g_hash_table_foreach (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x401b7)
    #4 0x559a21bf3c27 in object_class_foreach /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../qom/object.c:1092:5
    #5 0x559a21bf3c27 in object_class_get_list /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../qom/object.c:1149:5
    #6 0x559a2081a2fd in select_machine /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../softmmu/vl.c:1661:24
    #7 0x559a2081a2fd in qemu_create_machine /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../softmmu/vl.c:2146:35
    #8 0x559a2081a2fd in qemu_init /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../softmmu/vl.c:3706:5
    #9 0x559a20720ed5 in main /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../softmmu/main.c:49:5
    #10 0x7f09baec00b2 in __libc_start_main /build/glibc-sMfBJT/glibc-2.31/csu/../csu/libc-start.c:308:16
    #11 0x559a2067673d in _start (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/qemu-system-aarch64+0xf4b73d)

0x61000000ab00 is located 0 bytes to the right of 192-byte region [0x61000000aa40,0x61000000ab00)
allocated by thread T0 here:
    #0 0x559a206eeff2 in calloc (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/qemu-system-aarch64+0xfc3ff2)
    xen-project#1 0x7f09bcb7bef0 in g_malloc0 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x57ef0)
    #2 0x559a21bf3442 in object_class_foreach_tramp /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/san/../../qom/object.c:1070:5

Fixes: 00f05c0 ("hw/dma/xlnx_csu_dma: Support starting a read transfer through a class method")
Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Francisco Iglesias <[email protected]>
Reviewed-by: Edgar E. Iglesias <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: [email protected]
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jun 17, 2022
Include the qtest reproducer provided by Alexander Bulekov
in https://gitlab.com/qemu-project/qemu/-/issues/542.
Without the previous commit, we get:

  $ make check-qtest-i386
  ...
  Running test tests/qtest/intel-hda-test
  AddressSanitizer:DEADLYSIGNAL
  =================================================================
  ==1580408==ERROR: AddressSanitizer: stack-overflow on address 0x7ffc3d566fe0
      #0 0x63d297cf in address_space_translate_internal softmmu/physmem.c:356
      xen-project#1 0x63d27260 in flatview_do_translate softmmu/physmem.c:499:15
      #2 0x63d27af5 in flatview_translate softmmu/physmem.c:565:15
      #3 0x63d4ce84 in flatview_write softmmu/physmem.c:2850:10
      #4 0x63d4cb18 in address_space_write softmmu/physmem.c:2950:18
      #5 0x63d4d387 in address_space_rw softmmu/physmem.c:2960:16
      #6 0x62ae12f2 in dma_memory_rw_relaxed include/sysemu/dma.h:89:12
      #7 0x62ae104a in dma_memory_rw include/sysemu/dma.h:132:12
      #8 0x62ae6157 in dma_memory_write include/sysemu/dma.h:173:12
      #9 0x62ae5ec0 in stl_le_dma include/sysemu/dma.h:275:1
      #10 0x62ae5ba2 in stl_le_pci_dma include/hw/pci/pci.h:871:1
      #11 0x62ad59a6 in intel_hda_response hw/audio/intel-hda.c:372:12
      #12 0x62ad2afb in hda_codec_response hw/audio/intel-hda.c:107:5
      #13 0x62aec4e1 in hda_audio_command hw/audio/hda-codec.c:655:5
      #14 0x62ae05d9 in intel_hda_send_command hw/audio/intel-hda.c:307:5
      #15 0x62adff54 in intel_hda_corb_run hw/audio/intel-hda.c:342:9
      #16 0x62adc13b in intel_hda_set_corb_wp hw/audio/intel-hda.c:548:5
      #17 0x62ae5942 in intel_hda_reg_write hw/audio/intel-hda.c:977:9
      #18 0x62ada10a in intel_hda_mmio_write hw/audio/intel-hda.c:1054:5
      #19 0x63d8f383 in memory_region_write_accessor softmmu/memory.c:492:5
      #20 0x63d8ecc1 in access_with_adjusted_size softmmu/memory.c:554:18
      #21 0x63d8d5d6 in memory_region_dispatch_write softmmu/memory.c:1504:16
      #22 0x63d5e85e in flatview_write_continue softmmu/physmem.c:2812:23
      #23 0x63d4d05b in flatview_write softmmu/physmem.c:2854:12
      #24 0x63d4cb18 in address_space_write softmmu/physmem.c:2950:18
      #25 0x63d4d387 in address_space_rw softmmu/physmem.c:2960:16
      #26 0x62ae12f2 in dma_memory_rw_relaxed include/sysemu/dma.h:89:12
      #27 0x62ae104a in dma_memory_rw include/sysemu/dma.h:132:12
      #28 0x62ae6157 in dma_memory_write include/sysemu/dma.h:173:12
      #29 0x62ae5ec0 in stl_le_dma include/sysemu/dma.h:275:1
      #30 0x62ae5ba2 in stl_le_pci_dma include/hw/pci/pci.h:871:1
      #31 0x62ad59a6 in intel_hda_response hw/audio/intel-hda.c:372:12
      #32 0x62ad2afb in hda_codec_response hw/audio/intel-hda.c:107:5
      #33 0x62aec4e1 in hda_audio_command hw/audio/hda-codec.c:655:5
      #34 0x62ae05d9 in intel_hda_send_command hw/audio/intel-hda.c:307:5
      #35 0x62adff54 in intel_hda_corb_run hw/audio/intel-hda.c:342:9
      #36 0x62adc13b in intel_hda_set_corb_wp hw/audio/intel-hda.c:548:5
      #37 0x62ae5942 in intel_hda_reg_write hw/audio/intel-hda.c:977:9
      #38 0x62ada10a in intel_hda_mmio_write hw/audio/intel-hda.c:1054:5
      #39 0x63d8f383 in memory_region_write_accessor softmmu/memory.c:492:5
      #40 0x63d8ecc1 in access_with_adjusted_size softmmu/memory.c:554:18
      #41 0x63d8d5d6 in memory_region_dispatch_write softmmu/memory.c:1504:16
      #42 0x63d5e85e in flatview_write_continue softmmu/physmem.c:2812:23
      #43 0x63d4d05b in flatview_write softmmu/physmem.c:2854:12
      #44 0x63d4cb18 in address_space_write softmmu/physmem.c:2950:18
      #45 0x63d4d387 in address_space_rw softmmu/physmem.c:2960:16
      #46 0x62ae12f2 in dma_memory_rw_relaxed include/sysemu/dma.h:89:12
      #47 0x62ae104a in dma_memory_rw include/sysemu/dma.h:132:12
      #48 0x62ae6157 in dma_memory_write include/sysemu/dma.h:173:12
      ...
  SUMMARY: AddressSanitizer: stack-overflow softmmu/physmem.c:356 in address_space_translate_internal
  ==1580408==ABORTING
  Broken pipe
  Aborted (core dumped)

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Acked-by: Thomas Huth <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Thomas Huth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jun 17, 2022
The issue reported by OSS-Fuzz produces the following backtrace:

  ==447470==ERROR: AddressSanitizer: heap-buffer-overflow
  READ of size 1 at 0x61500002a080 thread T0
      #0 0x71766d47 in sdhci_read_dataport hw/sd/sdhci.c:474:18
      xen-project#1 0x7175f139 in sdhci_read hw/sd/sdhci.c:1022:19
      #2 0x721b937b in memory_region_read_accessor softmmu/memory.c:440:11
      #3 0x72171e51 in access_with_adjusted_size softmmu/memory.c:554:18
      #4 0x7216f47c in memory_region_dispatch_read1 softmmu/memory.c:1424:16
      #5 0x7216ebb9 in memory_region_dispatch_read softmmu/memory.c:1452:9
      #6 0x7212db5d in flatview_read_continue softmmu/physmem.c:2879:23
      #7 0x7212f958 in flatview_read softmmu/physmem.c:2921:12
      #8 0x7212f418 in address_space_read_full softmmu/physmem.c:2934:18
      #9 0x721305a9 in address_space_rw softmmu/physmem.c:2962:16
      #10 0x7175a392 in dma_memory_rw_relaxed include/sysemu/dma.h:89:12
      #11 0x7175a0ea in dma_memory_rw include/sysemu/dma.h:132:12
      #12 0x71759684 in dma_memory_read include/sysemu/dma.h:152:12
      #13 0x7175518c in sdhci_do_adma hw/sd/sdhci.c:823:27
      #14 0x7174bf69 in sdhci_data_transfer hw/sd/sdhci.c:935:13
      #15 0x7176aaa7 in sdhci_send_command hw/sd/sdhci.c:376:9
      #16 0x717629ee in sdhci_write hw/sd/sdhci.c:1212:9
      #17 0x72172513 in memory_region_write_accessor softmmu/memory.c:492:5
      #18 0x72171e51 in access_with_adjusted_size softmmu/memory.c:554:18
      #19 0x72170766 in memory_region_dispatch_write softmmu/memory.c:1504:16
      #20 0x721419ee in flatview_write_continue softmmu/physmem.c:2812:23
      #21 0x721301eb in flatview_write softmmu/physmem.c:2854:12
      #22 0x7212fca8 in address_space_write softmmu/physmem.c:2950:18
      #23 0x721d9a53 in qtest_process_command softmmu/qtest.c:727:9

A DMA descriptor is previously filled in RAM. An I/O access to the
device (frames #22 to #16) start the DMA engine (frame #13). The
engine fetch the descriptor and execute the request, which itself
accesses the SDHCI I/O registers (frame xen-project#1 and #0), triggering a
re-entrancy issue.

Fix by prohibit transactions from the DMA to devices. The DMA engine
is thus restricted to memories.

Reported-by: OSS-Fuzz (Issue 36391)
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/451
Message-Id: <[email protected]>
Signed-off-by: Thomas Huth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jun 17, 2022
Include the qtest reproducer provided by Alexander Bulekov
in https://gitlab.com/qemu-project/qemu/-/issues/451. Without
the previous commit, we get:

  $ make check-qtest-i386
  ...
  Running test qtest-i386/fuzz-sdcard-test
  ==447470==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61500002a080 at pc 0x564c71766d48 bp 0x7ffc126c62b0 sp 0x7ffc126c62a8
  READ of size 1 at 0x61500002a080 thread T0
      #0 0x564c71766d47 in sdhci_read_dataport hw/sd/sdhci.c:474:18
      xen-project#1 0x564c7175f139 in sdhci_read hw/sd/sdhci.c:1022:19
      #2 0x564c721b937b in memory_region_read_accessor softmmu/memory.c:440:11
      #3 0x564c72171e51 in access_with_adjusted_size softmmu/memory.c:554:18
      #4 0x564c7216f47c in memory_region_dispatch_read1 softmmu/memory.c:1424:16
      #5 0x564c7216ebb9 in memory_region_dispatch_read softmmu/memory.c:1452:9
      #6 0x564c7212db5d in flatview_read_continue softmmu/physmem.c:2879:23
      #7 0x564c7212f958 in flatview_read softmmu/physmem.c:2921:12
      #8 0x564c7212f418 in address_space_read_full softmmu/physmem.c:2934:18
      #9 0x564c721305a9 in address_space_rw softmmu/physmem.c:2962:16
      #10 0x564c7175a392 in dma_memory_rw_relaxed include/sysemu/dma.h:89:12
      #11 0x564c7175a0ea in dma_memory_rw include/sysemu/dma.h:132:12
      #12 0x564c71759684 in dma_memory_read include/sysemu/dma.h:152:12
      #13 0x564c7175518c in sdhci_do_adma hw/sd/sdhci.c:823:27
      #14 0x564c7174bf69 in sdhci_data_transfer hw/sd/sdhci.c:935:13
      #15 0x564c7176aaa7 in sdhci_send_command hw/sd/sdhci.c:376:9
      #16 0x564c717629ee in sdhci_write hw/sd/sdhci.c:1212:9
      #17 0x564c72172513 in memory_region_write_accessor softmmu/memory.c:492:5
      #18 0x564c72171e51 in access_with_adjusted_size softmmu/memory.c:554:18
      #19 0x564c72170766 in memory_region_dispatch_write softmmu/memory.c:1504:16
      #20 0x564c721419ee in flatview_write_continue softmmu/physmem.c:2812:23
      #21 0x564c721301eb in flatview_write softmmu/physmem.c:2854:12
      #22 0x564c7212fca8 in address_space_write softmmu/physmem.c:2950:18
      #23 0x564c721d9a53 in qtest_process_command softmmu/qtest.c:727:9

  0x61500002a080 is located 0 bytes to the right of 512-byte region [0x615000029e80,0x61500002a080)
  allocated by thread T0 here:
      #0 0x564c708e1737 in __interceptor_calloc (qemu-system-i386+0x1e6a737)
      xen-project#1 0x7ff05567b5e0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5a5e0)
      #2 0x564c71774adb in sdhci_pci_realize hw/sd/sdhci-pci.c:36:5

  SUMMARY: AddressSanitizer: heap-buffer-overflow hw/sd/sdhci.c:474:18 in sdhci_read_dataport
  Shadow bytes around the buggy address:
    0x0c2a7fffd3c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
    0x0c2a7fffd3d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c2a7fffd3e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c2a7fffd3f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c2a7fffd400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  =>0x0c2a7fffd410:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
    0x0c2a7fffd420: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c2a7fffd430: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c2a7fffd440: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c2a7fffd450: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c2a7fffd460: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Heap left redzone:       fa
    Freed heap region:       fd
  ==447470==ABORTING
  Broken pipe
  ERROR qtest-i386/fuzz-sdcard-test - too few tests run (expected 3, got 2)

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Acked-by: Thomas Huth <[email protected]>
Message-Id: <[email protected]>
[thuth: Replaced "-m 4G" with "-m 512M"]
Signed-off-by: Thomas Huth <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jun 17, 2022
Since commit 0439c5a ("block/block-backend.c: assertions for
block-backend") QEMU crashes when using Cocoa on Darwin hosts.

Example on macOS:

  $ qemu-system-i386
  Assertion failed: (qemu_in_main_thread()), function blk_all_next, file block-backend.c, line 552.
  Abort trap: 6

Looking with lldb:

  Assertion failed: (qemu_in_main_thread()), function blk_all_next, file block-backend.c, line 552.
  Process 76914 stopped
  * thread xen-project#1, queue = 'com.apple.main-thread', stop reason = hit program assert
     frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1
  at block-backend.c:552:5 [opt]
      549    */
      550   BlockBackend *blk_all_next(BlockBackend *blk)
      551   {
  --> 552       GLOBAL_STATE_CODE();
      553       return blk ? QTAILQ_NEXT(blk, link)
      554                  : QTAILQ_FIRST(&block_backends);
      555   }
  Target 1: (qemu-system-i386) stopped.

  (lldb) bt
  * thread xen-project#1, queue = 'com.apple.main-thread', stop reason = hit program assert
     frame #0: 0x00000001908c99b8 libsystem_kernel.dylib`__pthread_kill + 8
     frame xen-project#1: 0x00000001908fceb0 libsystem_pthread.dylib`pthread_kill + 288
     frame #2: 0x000000019083a314 libsystem_c.dylib`abort + 164
     frame #3: 0x000000019083972c libsystem_c.dylib`__assert_rtn + 300
   * frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1 at block-backend.c:552:5 [opt]
     frame #5: 0x00000001003c00b4 qemu-system-i386`blk_all_next(blk=<unavailable>) at block-backend.c:552:5 [opt]
     frame #6: 0x00000001003d8f04 qemu-system-i386`qmp_query_block(errp=0x0000000000000000) at qapi.c:591:16 [opt]
     frame #7: 0x000000010003ab0c qemu-system-i386`main [inlined] addRemovableDevicesMenuItems at cocoa.m:1756:21 [opt]
     frame #8: 0x000000010003ab04 qemu-system-i386`main(argc=<unavailable>, argv=<unavailable>) at cocoa.m:1980:5 [opt]
     frame #9: 0x00000001012690f4 dyld`start + 520

As we are in passed release 7.0 hard freeze, disable the block
backend assertion which, while being valuable during development,
is not helpful to users. We'll restore this assertion immediately
once 7.0 is released and work on a fix.

Suggested-by: Akihiko Odaki <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Akihiko Odaki <[email protected]>
Reviewed-by: Peter Maydell <[email protected]>
Message-Id: <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Dec 16, 2022
Fix warnings such:

  disas/nanomips.c:3251:64: warning: format specifies type 'char *' but the argument has type 'int64' (aka 'long long') [-Wformat]
    return img_format("CACHE 0x%" PRIx64 ", %s(%s)", op_value, s_value, rs);
                                            ~~                 ^~~~~~~
                                            %lld

To avoid crashes such (kernel from commit f375ad6):

  $ qemu-system-mipsel -cpu I7200 -d in_asm -kernel generic_nano32r6el_page4k
  ...
  ----------------
  IN: __bzero
  0x805c6084:  20c4 6950      ADDU r13, a0, a2
  0x805c6088:  9089           ADDIU a0, 1
  Process 70261 stopped
  * thread #6, stop reason = EXC_BAD_ACCESS (code=1, address=0xfffffffffffffff0)
      frame #0: 0x00000001bfe38864 libsystem_platform.dylib`_platform_strlen + 4
  libsystem_platform.dylib`:
  ->  0x1bfe38864 <+4>:  ldr    q0, [x1]
      0x1bfe38868 <+8>:  adr    x3, #-0xc8                ; ___lldb_unnamed_symbol314
      0x1bfe3886c <+12>: ldr    q2, [x3], #0x10
      0x1bfe38870 <+16>: and    x2, x0, #0xf
  Target 0: (qemu-system-mipsel) stopped.
  (lldb) bt
  * thread #6, stop reason = EXC_BAD_ACCESS (code=1, address=0xfffffffffffffff0)
    * frame #0: 0x00000001bfe38864 libsystem_platform.dylib`_platform_strlen + 4
      frame xen-project#1: 0x00000001bfce76a0 libsystem_c.dylib`__vfprintf + 4544
      frame #2: 0x00000001bfd158b4 libsystem_c.dylib`_vasprintf + 280
      frame #3: 0x0000000101c22fb0 libglib-2.0.0.dylib`g_vasprintf + 28
      frame #4: 0x0000000101bfb7d8 libglib-2.0.0.dylib`g_strdup_vprintf + 32
      frame #5: 0x000000010000fb70 qemu-system-mipsel`img_format(format=<unavailable>) at nanomips.c:103:14 [opt]
      frame #6: 0x0000000100018868 qemu-system-mipsel`SB_S9_(instruction=<unavailable>, info=<unavailable>) at nanomips.c:12616:12 [opt]
      frame #7: 0x000000010000f90c qemu-system-mipsel`print_insn_nanomips at nanomips.c:589:28 [opt]

Fixes: 4066c15 ("disas/nanomips: Remove IMMEDIATE functions")
Reported-by: Stefan Weil <[email protected]>
Reviewed-by: Stefan Weil <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jul 21, 2023
After live migration with virtio block device, qemu crash at:

	#0  0x000055914f46f795 in object_dynamic_cast_assert (obj=0x559151b7b090, typename=0x55914f80fbc4 "qio-channel", file=0x55914f80fb90 "/images/testvfe/sw/qemu.gerrit/include/io/channel.h", line=30, func=0x55914f80fcb8 <__func__.17257> "QIO_CHANNEL") at ../qom/object.c:872
	xen-project#1  0x000055914f480d68 in QIO_CHANNEL (obj=0x559151b7b090) at /images/testvfe/sw/qemu.gerrit/include/io/channel.h:29
	#2  0x000055914f4812f8 in qio_net_listener_set_client_func_full (listener=0x559151b7a720, func=0x55914f580b97 <tcp_chr_accept>, data=0x5591519f4ea0, notify=0x0, context=0x0) at ../io/net-listener.c:166
	#3  0x000055914f580059 in tcp_chr_update_read_handler (chr=0x5591519f4ea0) at ../chardev/char-socket.c:637
	#4  0x000055914f583dca in qemu_chr_be_update_read_handlers (s=0x5591519f4ea0, context=0x0) at ../chardev/char.c:226
	#5  0x000055914f57b7c9 in qemu_chr_fe_set_handlers_full (b=0x559152bf23a0, fd_can_read=0x0, fd_read=0x0, fd_event=0x0, be_change=0x0, opaque=0x0, context=0x0, set_open=false, sync_state=true) at ../chardev/char-fe.c:279
	#6  0x000055914f57b86d in qemu_chr_fe_set_handlers (b=0x559152bf23a0, fd_can_read=0x0, fd_read=0x0, fd_event=0x0, be_change=0x0, opaque=0x0, context=0x0, set_open=false) at ../chardev/char-fe.c:304
	#7  0x000055914f378caf in vhost_user_async_close (d=0x559152bf21a0, chardev=0x559152bf23a0, vhost=0x559152bf2420, cb=0x55914f2fb8c1 <vhost_user_blk_disconnect>) at ../hw/virtio/vhost-user.c:2725
	#8  0x000055914f2fba40 in vhost_user_blk_event (opaque=0x559152bf21a0, event=CHR_EVENT_CLOSED) at ../hw/block/vhost-user-blk.c:395
	#9  0x000055914f58388c in chr_be_event (s=0x5591519f4ea0, event=CHR_EVENT_CLOSED) at ../chardev/char.c:61
	#10 0x000055914f583905 in qemu_chr_be_event (s=0x5591519f4ea0, event=CHR_EVENT_CLOSED) at ../chardev/char.c:81
	#11 0x000055914f581275 in char_socket_finalize (obj=0x5591519f4ea0) at ../chardev/char-socket.c:1083
	#12 0x000055914f46f073 in object_deinit (obj=0x5591519f4ea0, type=0x5591519055c0) at ../qom/object.c:680
	#13 0x000055914f46f0e5 in object_finalize (data=0x5591519f4ea0) at ../qom/object.c:694
	#14 0x000055914f46ff06 in object_unref (objptr=0x5591519f4ea0) at ../qom/object.c:1202
	#15 0x000055914f4715a4 in object_finalize_child_property (obj=0x559151b76c50, name=0x559151b7b250 "char3", opaque=0x5591519f4ea0) at ../qom/object.c:1747
	#16 0x000055914f46ee86 in object_property_del_all (obj=0x559151b76c50) at ../qom/object.c:632
	#17 0x000055914f46f0d2 in object_finalize (data=0x559151b76c50) at ../qom/object.c:693
	#18 0x000055914f46ff06 in object_unref (objptr=0x559151b76c50) at ../qom/object.c:1202
	#19 0x000055914f4715a4 in object_finalize_child_property (obj=0x559151b6b560, name=0x559151b76630 "chardevs", opaque=0x559151b76c50) at ../qom/object.c:1747
	#20 0x000055914f46ef67 in object_property_del_child (obj=0x559151b6b560, child=0x559151b76c50) at ../qom/object.c:654
	#21 0x000055914f46f042 in object_unparent (obj=0x559151b76c50) at ../qom/object.c:673
	#22 0x000055914f58632a in qemu_chr_cleanup () at ../chardev/char.c:1189
	#23 0x000055914f16c66c in qemu_cleanup () at ../softmmu/runstate.c:830
	#24 0x000055914eee7b9e in qemu_default_main () at ../softmmu/main.c:38
	#25 0x000055914eee7bcc in main (argc=86, argv=0x7ffc97cb8d88) at ../softmmu/main.c:48

In char_socket_finalize after s->listener freed, event callback function
vhost_user_blk_event will be called to handle CHR_EVENT_CLOSED.
vhost_user_blk_event is calling qio_net_listener_set_client_func_full which
is still using s->listener.

Setting s->listener = NULL after object_unref(OBJECT(s->listener)) can
solve this issue.

Signed-off-by: Yajun Wu <[email protected]>
Acked-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Marc-André Lureau <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
(cherry picked from commit b8a7f51)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jul 21, 2023
For ex, when resetting the xlnx-zcu102 machine:

(lldb) bt
* thread xen-project#1, queue = 'com.apple.main-thread', stop reason =
EXC_BAD_ACCESS (code=1, address=0x50)
   * frame #0: 0x10020a740 gd_vc_send_chars(vc=0x000000000) at
gtk.c:1759:41 [opt]
     frame xen-project#1: 0x100636264 qemu_chr_fe_accept_input(be=<unavailable>) at
char-fe.c:159:9 [opt]
     frame #2: 0x1000608e0 cadence_uart_reset_hold [inlined]
uart_rx_reset(s=0x10810a960) at cadence_uart.c:158:5 [opt]
     frame #3: 0x1000608d4 cadence_uart_reset_hold(obj=0x10810a960) at
cadence_uart.c:530:5 [opt]
     frame #4: 0x100580ab4 resettable_phase_hold(obj=0x10810a960,
opaque=0x000000000, type=<unavailable>) at resettable.c:0 [opt]
     frame #5: 0x10057d1b0 bus_reset_child_foreach(obj=<unavailable>,
cb=(resettable_phase_hold at resettable.c:162), opaque=0x000000000,
type=RESET_TYPE_COLD) at bus.c:97:13 [opt]
     frame #6: 0x1005809f8 resettable_phase_hold [inlined]
resettable_child_foreach(rc=0x000060000332d2c0, obj=0x0000600002c1c180,
cb=<unavailable>, opaque=0x000000000, type=RESET_TYPE_COLD) at
resettable.c:96:9 [opt]
     frame #7: 0x1005809d8 resettable_phase_hold(obj=0x0000600002c1c180,
opaque=0x000000000, type=RESET_TYPE_COLD) at resettable.c:173:5 [opt]
     frame #8: 0x1005803a0
resettable_assert_reset(obj=0x0000600002c1c180, type=<unavailable>) at
resettable.c:60:5 [opt]
     frame #9: 0x10058027c resettable_reset(obj=0x0000600002c1c180,
type=RESET_TYPE_COLD) at resettable.c:45:5 [opt]

While the chardev is created early, the VirtualConsole is associated
after, during qemu_init_displays().

Signed-off-by: Marc-André Lureau <[email protected]>
Tested-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
(cherry picked from commit 49152ac)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jul 21, 2023
Command "qemu-system-riscv64 -machine virt
-m 2G -smp 1 -numa node,mem=1G -numa node,mem=1G"
would trigger this problem.Backtrace with:
 #0  0x0000555555b5b1a4 in riscv_numa_get_default_cpu_node_id  at ../hw/riscv/numa.c:211
 xen-project#1  0x00005555558ce510 in machine_numa_finish_cpu_init  at ../hw/core/machine.c:1230
 #2  0x00005555558ce9d3 in machine_run_board_init  at ../hw/core/machine.c:1346
 #3  0x0000555555aaedc3 in qemu_init_board  at ../softmmu/vl.c:2513
 #4  0x0000555555aaf064 in qmp_x_exit_preconfig  at ../softmmu/vl.c:2609
 #5  0x0000555555ab1916 in qemu_init  at ../softmmu/vl.c:3617
 #6  0x000055555585463b in main  at ../softmmu/main.c:47
This commit fixes the issue by adding parameter checks.

Reviewed-by: Alistair Francis <[email protected]>
Reviewed-by: Daniel Henrique Barboza <[email protected]>
Reviewed-by: LIU Zhiwei <[email protected]>
Reviewed-by: Weiwei Li <[email protected]>
Signed-off-by: Yin Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alistair Francis <[email protected]>
(cherry picked from commit b9cedbf)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Jul 21, 2023
vhost_dev_start function does not release memory_listener object
in case of an error. This may crash the guest when vhost is unable
to set memory table:

  stack trace of thread 125653:
  Program terminated with signal SIGSEGV, Segmentation fault
  #0  memory_listener_register (qemu-kvm + 0x6cda0f)
  xen-project#1  vhost_dev_start (qemu-kvm + 0x699301)
  #2  vhost_net_start (qemu-kvm + 0x45b03f)
  #3  virtio_net_set_status (qemu-kvm + 0x665672)
  #4  qmp_set_link (qemu-kvm + 0x548fd5)
  #5  net_vhost_user_event (qemu-kvm + 0x552c45)
  #6  tcp_chr_connect (qemu-kvm + 0x88d473)
  #7  tcp_chr_new_client (qemu-kvm + 0x88cf83)
  #8  tcp_chr_accept (qemu-kvm + 0x88b429)
  #9  qio_net_listener_channel_func (qemu-kvm + 0x7ac07c)
  #10 g_main_context_dispatch (libglib-2.0.so.0 + 0x54e2f)

Release memory_listener objects in the error path.

Signed-off-by: Prasad Pandit <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Fixes: c471ad0 ("vhost_net: device IOTLB support")
Cc: [email protected]
Acked-by: Jason Wang <[email protected]>
(cherry picked from commit 1e3ffb3)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
This leakage can be seen through test-io-channel-tls:

$ ../configure --target-list=aarch64-softmmu --enable-sanitizers
$ make ./tests/unit/test-io-channel-tls
$ ./tests/unit/test-io-channel-tls

Indirect leak of 104 byte(s) in 1 object(s) allocated from:
    #0 0x7f81d1725808 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:144
    xen-project#1 0x7f81d135ae98 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x57e98)
    #2 0x55616c5d4c1b in object_new_with_propv ../qom/object.c:795
    #3 0x55616c5d4a83 in object_new_with_props ../qom/object.c:768
    #4 0x55616c5c5415 in test_tls_creds_create ../tests/unit/test-io-channel-tls.c:70
    #5 0x55616c5c5a6b in test_io_channel_tls ../tests/unit/test-io-channel-tls.c:158
    #6 0x7f81d137d58d  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a58d)

Indirect leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7f81d1725a06 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:153
    xen-project#1 0x7f81d1472a20 in gnutls_dh_params_init (/lib/x86_64-linux-gnu/libgnutls.so.30+0x46a20)
    #2 0x55616c6485ff in qcrypto_tls_creds_x509_load ../crypto/tlscredsx509.c:634
    #3 0x55616c648ba2 in qcrypto_tls_creds_x509_complete ../crypto/tlscredsx509.c:694
    #4 0x55616c5e1fea in user_creatable_complete ../qom/object_interfaces.c:28
    #5 0x55616c5d4c8c in object_new_with_propv ../qom/object.c:807
    #6 0x55616c5d4a83 in object_new_with_props ../qom/object.c:768
    #7 0x55616c5c5415 in test_tls_creds_create ../tests/unit/test-io-channel-tls.c:70
    #8 0x55616c5c5a6b in test_io_channel_tls ../tests/unit/test-io-channel-tls.c:158
    #9 0x7f81d137d58d  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a58d)

...

SUMMARY: AddressSanitizer: 49143 byte(s) leaked in 184 allocation(s).

The docs for `g_source_add_child_source(source, child_source)` says
"source will hold a reference on child_source while child_source is
attached to it." Therefore, we should unreference the child source at
`qio_channel_tls_read_watch()` after attaching it to `source`. With this
change, ./tests/unit/test-io-channel-tls shows no leakages.

Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Matheus Tavares Bernardino <[email protected]>
Signed-off-by: Daniel P. Berrangé <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
xbzrle_encode_buffer_avx512() checks for overflows too scarcely in its
outer loop, causing out-of-bounds writes:

$ ../configure --target-list=aarch64-softmmu --enable-sanitizers --enable-avx512bw
$ make tests/unit/test-xbzrle && ./tests/unit/test-xbzrle

==5518==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62100000b100 at pc 0x561109a7714d bp 0x7ffed712a440 sp 0x7ffed712a430
WRITE of size 1 at 0x62100000b100 thread T0
    #0 0x561109a7714c in uleb128_encode_small ../util/cutils.c:831
    xen-project#1 0x561109b67f6a in xbzrle_encode_buffer_avx512 ../migration/xbzrle.c:275
    #2 0x5611099a7428 in test_encode_decode_overflow ../tests/unit/test-xbzrle.c:153
    #3 0x7fb2fb65a58d  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a58d)
    #4 0x7fb2fb65a333  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a333)
    #5 0x7fb2fb65aa79 in g_test_run_suite (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7aa79)
    #6 0x7fb2fb65aa94 in g_test_run (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7aa94)
    #7 0x5611099a3a23 in main ../tests/unit/test-xbzrle.c:218
    #8 0x7fb2fa78c082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082)
    #9 0x5611099a608d in _start (/qemu/build/tests/unit/test-xbzrle+0x28408d)

0x62100000b100 is located 0 bytes to the right of 4096-byte region [0x62100000a100,0x62100000b100)
allocated by thread T0 here:
    #0 0x7fb2fb823a06 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:153
    xen-project#1 0x7fb2fb637ef0 in g_malloc0 (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x57ef0)

Fix that by performing the overflow check in the inner loop, instead.

Signed-off-by: Matheus Tavares Bernardino <[email protected]>
Reviewed-by: Dr. David Alan Gilbert <[email protected]>
Reviewed-by: Juan Quintela <[email protected]>
Signed-off-by: Juan Quintela <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
For ex, when resetting the xlnx-zcu102 machine:

(lldb) bt
* thread xen-project#1, queue = 'com.apple.main-thread', stop reason =
EXC_BAD_ACCESS (code=1, address=0x50)
   * frame #0: 0x10020a740 gd_vc_send_chars(vc=0x000000000) at
gtk.c:1759:41 [opt]
     frame xen-project#1: 0x100636264 qemu_chr_fe_accept_input(be=<unavailable>) at
char-fe.c:159:9 [opt]
     frame #2: 0x1000608e0 cadence_uart_reset_hold [inlined]
uart_rx_reset(s=0x10810a960) at cadence_uart.c:158:5 [opt]
     frame #3: 0x1000608d4 cadence_uart_reset_hold(obj=0x10810a960) at
cadence_uart.c:530:5 [opt]
     frame #4: 0x100580ab4 resettable_phase_hold(obj=0x10810a960,
opaque=0x000000000, type=<unavailable>) at resettable.c:0 [opt]
     frame #5: 0x10057d1b0 bus_reset_child_foreach(obj=<unavailable>,
cb=(resettable_phase_hold at resettable.c:162), opaque=0x000000000,
type=RESET_TYPE_COLD) at bus.c:97:13 [opt]
     frame #6: 0x1005809f8 resettable_phase_hold [inlined]
resettable_child_foreach(rc=0x000060000332d2c0, obj=0x0000600002c1c180,
cb=<unavailable>, opaque=0x000000000, type=RESET_TYPE_COLD) at
resettable.c:96:9 [opt]
     frame #7: 0x1005809d8 resettable_phase_hold(obj=0x0000600002c1c180,
opaque=0x000000000, type=RESET_TYPE_COLD) at resettable.c:173:5 [opt]
     frame #8: 0x1005803a0
resettable_assert_reset(obj=0x0000600002c1c180, type=<unavailable>) at
resettable.c:60:5 [opt]
     frame #9: 0x10058027c resettable_reset(obj=0x0000600002c1c180,
type=RESET_TYPE_COLD) at resettable.c:45:5 [opt]

While the chardev is created early, the VirtualConsole is associated
after, during qemu_init_displays().

Signed-off-by: Marc-André Lureau <[email protected]>
Tested-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
blk_get_geometry() eventually calls bdrv_nb_sectors(), which is a
co_wrapper_mixed_bdrv_rdlock. This means that when it is called from
coroutine context, it already assume to have the graph locked.

However, virtio_blk_sect_range_ok() in block/export/virtio-blk-handler.c
(used by vhost-user-blk and VDUSE exports) runs in a coroutine, but
doesn't take the graph lock - blk_*() functions are generally expected
to do that internally. This causes an assertion failure when accessing
an export for the first time if it runs in an iothread.

This is an example of the crash:

  $ ./storage-daemon/qemu-storage-daemon --object iothread,id=th0 --blockdev file,filename=/home/kwolf/images/hd.img,node-name=disk --export vhost-user-blk,addr.type=unix,addr.path=/tmp/vhost.sock,node-name=disk,id=exp0,iothread=th0
  qemu-storage-daemon: ../block/graph-lock.c:268: void assert_bdrv_graph_readable(void): Assertion `qemu_in_main_thread() || reader_count()' failed.

  (gdb) bt
  #0  0x00007ffff6eafe5c in __pthread_kill_implementation () from /lib64/libc.so.6
  xen-project#1  0x00007ffff6e5fa76 in raise () from /lib64/libc.so.6
  #2  0x00007ffff6e497fc in abort () from /lib64/libc.so.6
  #3  0x00007ffff6e4971b in __assert_fail_base.cold () from /lib64/libc.so.6
  #4  0x00007ffff6e58656 in __assert_fail () from /lib64/libc.so.6
  #5  0x00005555556337a3 in assert_bdrv_graph_readable () at ../block/graph-lock.c:268
  #6  0x00005555555fd5a2 in bdrv_co_nb_sectors (bs=0x5555564c5ef0) at ../block.c:5847
  #7  0x00005555555ee949 in bdrv_nb_sectors (bs=0x5555564c5ef0) at block/block-gen.c:256
  #8  0x00005555555fd6b9 in bdrv_get_geometry (bs=0x5555564c5ef0, nb_sectors_ptr=0x7fffef7fedd0) at ../block.c:5884
  #9  0x000055555562ad6d in blk_get_geometry (blk=0x5555564cb200, nb_sectors_ptr=0x7fffef7fedd0) at ../block/block-backend.c:1624
  #10 0x00005555555ddb74 in virtio_blk_sect_range_ok (blk=0x5555564cb200, block_size=512, sector=0, size=512) at ../block/export/virtio-blk-handler.c:44
  #11 0x00005555555dd80d in virtio_blk_process_req (handler=0x5555564cbb98, in_iov=0x7fffe8003830, out_iov=0x7fffe8003860, in_num=1, out_num=0) at ../block/export/virtio-blk-handler.c:189
  #12 0x00005555555dd546 in vu_blk_virtio_process_req (opaque=0x7fffe8003800) at ../block/export/vhost-user-blk-server.c:66
  #13 0x00005555557bf4a1 in coroutine_trampoline (i0=-402635264, i1=32767) at ../util/coroutine-ucontext.c:177
  #14 0x00007ffff6e75c20 in ?? () from /lib64/libc.so.6
  #15 0x00007fffefffa870 in ?? ()
  #16 0x0000000000000000 in ?? ()

Fix this by creating a new blk_co_get_geometry() that takes the lock,
and changing blk_get_geometry() to be a co_wrapper_mixed around it.

To make the resulting code cleaner, virtio-blk-handler.c can directly
call the coroutine version now (though that wouldn't be necessary for
fixing the bug, taking the lock in blk_co_get_geometry() is what fixes
it).

Fixes: 8ab8140
Reported-by: Lukáš Doktor <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Emanuele Giuseppe Esposito <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
Command "qemu-system-riscv64 -machine virt
-m 2G -smp 1 -numa node,mem=1G -numa node,mem=1G"
would trigger this problem.Backtrace with:
 #0  0x0000555555b5b1a4 in riscv_numa_get_default_cpu_node_id  at ../hw/riscv/numa.c:211
 xen-project#1  0x00005555558ce510 in machine_numa_finish_cpu_init  at ../hw/core/machine.c:1230
 #2  0x00005555558ce9d3 in machine_run_board_init  at ../hw/core/machine.c:1346
 #3  0x0000555555aaedc3 in qemu_init_board  at ../softmmu/vl.c:2513
 #4  0x0000555555aaf064 in qmp_x_exit_preconfig  at ../softmmu/vl.c:2609
 #5  0x0000555555ab1916 in qemu_init  at ../softmmu/vl.c:3617
 #6  0x000055555585463b in main  at ../softmmu/main.c:47
This commit fixes the issue by adding parameter checks.

Reviewed-by: Alistair Francis <[email protected]>
Reviewed-by: Daniel Henrique Barboza <[email protected]>
Reviewed-by: LIU Zhiwei <[email protected]>
Reviewed-by: Weiwei Li <[email protected]>
Signed-off-by: Yin Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alistair Francis <[email protected]>
(cherry picked from commit b9cedbf)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
vhost_dev_start function does not release memory_listener object
in case of an error. This may crash the guest when vhost is unable
to set memory table:

  stack trace of thread 125653:
  Program terminated with signal SIGSEGV, Segmentation fault
  #0  memory_listener_register (qemu-kvm + 0x6cda0f)
  xen-project#1  vhost_dev_start (qemu-kvm + 0x699301)
  #2  vhost_net_start (qemu-kvm + 0x45b03f)
  #3  virtio_net_set_status (qemu-kvm + 0x665672)
  #4  qmp_set_link (qemu-kvm + 0x548fd5)
  #5  net_vhost_user_event (qemu-kvm + 0x552c45)
  #6  tcp_chr_connect (qemu-kvm + 0x88d473)
  #7  tcp_chr_new_client (qemu-kvm + 0x88cf83)
  #8  tcp_chr_accept (qemu-kvm + 0x88b429)
  #9  qio_net_listener_channel_func (qemu-kvm + 0x7ac07c)
  #10 g_main_context_dispatch (libglib-2.0.so.0 + 0x54e2f)

Release memory_listener objects in the error path.

Signed-off-by: Prasad Pandit <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Fixes: c471ad0 ("vhost_net: device IOTLB support")
Cc: [email protected]
Acked-by: Jason Wang <[email protected]>
(cherry picked from commit 1e3ffb3)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Aug 17, 2023
in order to avoid requests being stuck in a BlockBackend's request
queue during cleanup. Having such requests can lead to a deadlock [0]
with a virtio-scsi-pci device using iothread that's busy with IO when
initiating a shutdown with QMP 'quit'.

There is a race where such a queued request can continue sometime
(maybe after bdrv_child_free()?) during bdrv_root_unref_child() [1].
The completion will hold the AioContext lock and wait for the BQL
during SCSI completion, but the main thread will hold the BQL and
wait for the AioContext as part of bdrv_root_unref_child(), leading to
the deadlock [0].

[0]:

> Thread 3 (Thread 0x7f3bbd87b700 (LWP 135952) "qemu-system-x86"):
> #0  __lll_lock_wait (futex=futex@entry=0x564183365f00 <qemu_global_mutex>, private=0) at lowlevellock.c:52
> xen-project#1  0x00007f3bc1c0d843 in __GI___pthread_mutex_lock (mutex=0x564183365f00 <qemu_global_mutex>) at ../nptl/pthread_mutex_lock.c:80
> #2  0x0000564182939f2e in qemu_mutex_lock_impl (mutex=0x564183365f00 <qemu_global_mutex>, file=0x564182b7f774 "../softmmu/physmem.c", line=2593) at ../util/qemu-thread-posix.c:94
> #3  0x000056418247cc2a in qemu_mutex_lock_iothread_impl (file=0x564182b7f774 "../softmmu/physmem.c", line=2593) at ../softmmu/cpus.c:504
> #4  0x00005641826d5325 in prepare_mmio_access (mr=0x5641856148a0) at ../softmmu/physmem.c:2593
> #5  0x00005641826d6fe7 in address_space_stl_internal (as=0x56418679b310, addr=4276113408, val=16418, attrs=..., result=0x0, endian=DEVICE_LITTLE_ENDIAN) at /home/febner/repos/qemu/memory_ldst.c.inc:318
> #6  0x00005641826d7154 in address_space_stl_le (as=0x56418679b310, addr=4276113408, val=16418, attrs=..., result=0x0) at /home/febner/repos/qemu/memory_ldst.c.inc:357
> #7  0x0000564182374b07 in pci_msi_trigger (dev=0x56418679b0d0, msg=...) at ../hw/pci/pci.c:359
> #8  0x000056418237118b in msi_send_message (dev=0x56418679b0d0, msg=...) at ../hw/pci/msi.c:379
> #9  0x0000564182372c10 in msix_notify (dev=0x56418679b0d0, vector=8) at ../hw/pci/msix.c:542
> #10 0x000056418243719c in virtio_pci_notify (d=0x56418679b0d0, vector=8) at ../hw/virtio/virtio-pci.c:77
> #11 0x00005641826933b0 in virtio_notify_vector (vdev=0x5641867a34a0, vector=8) at ../hw/virtio/virtio.c:1985
> #12 0x00005641826948d6 in virtio_irq (vq=0x5641867ac078) at ../hw/virtio/virtio.c:2461
> #13 0x0000564182694978 in virtio_notify (vdev=0x5641867a34a0, vq=0x5641867ac078) at ../hw/virtio/virtio.c:2473
> #14 0x0000564182665b83 in virtio_scsi_complete_req (req=0x7f3bb000e5d0) at ../hw/scsi/virtio-scsi.c:115
> #15 0x00005641826670ce in virtio_scsi_complete_cmd_req (req=0x7f3bb000e5d0) at ../hw/scsi/virtio-scsi.c:641
> #16 0x000056418266736b in virtio_scsi_command_complete (r=0x7f3bb0010560, resid=0) at ../hw/scsi/virtio-scsi.c:712
> #17 0x000056418239aac6 in scsi_req_complete (req=0x7f3bb0010560, status=2) at ../hw/scsi/scsi-bus.c:1526
> #18 0x000056418239e090 in scsi_handle_rw_error (r=0x7f3bb0010560, ret=-123, acct_failed=false) at ../hw/scsi/scsi-disk.c:242
> #19 0x000056418239e13f in scsi_disk_req_check_error (r=0x7f3bb0010560, ret=-123, acct_failed=false) at ../hw/scsi/scsi-disk.c:265
> #20 0x000056418239e482 in scsi_dma_complete_noio (r=0x7f3bb0010560, ret=-123) at ../hw/scsi/scsi-disk.c:340
> #21 0x000056418239e5d9 in scsi_dma_complete (opaque=0x7f3bb0010560, ret=-123) at ../hw/scsi/scsi-disk.c:371
> #22 0x00005641824809ad in dma_complete (dbs=0x7f3bb000d9d0, ret=-123) at ../softmmu/dma-helpers.c:107
> #23 0x0000564182480a72 in dma_blk_cb (opaque=0x7f3bb000d9d0, ret=-123) at ../softmmu/dma-helpers.c:127
> #24 0x00005641827bf78a in blk_aio_complete (acb=0x7f3bb00021a0) at ../block/block-backend.c:1563
> #25 0x00005641827bfa5e in blk_aio_write_entry (opaque=0x7f3bb00021a0) at ../block/block-backend.c:1630
> #26 0x000056418295638a in coroutine_trampoline (i0=-1342102448, i1=32571) at ../util/coroutine-ucontext.c:177
> #27 0x00007f3bc0caed40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
> #28 0x00007f3bbd8757f0 in ?? ()
> #29 0x0000000000000000 in ?? ()
>
> Thread 1 (Thread 0x7f3bbe3e9280 (LWP 135944) "qemu-system-x86"):
> #0  __lll_lock_wait (futex=futex@entry=0x5641856f2a00, private=0) at lowlevellock.c:52
> xen-project#1  0x00007f3bc1c0d8d1 in __GI___pthread_mutex_lock (mutex=0x5641856f2a00) at ../nptl/pthread_mutex_lock.c:115
> #2  0x0000564182939f2e in qemu_mutex_lock_impl (mutex=0x5641856f2a00, file=0x564182c0e319 "../util/async.c", line=728) at ../util/qemu-thread-posix.c:94
> #3  0x000056418293a140 in qemu_rec_mutex_lock_impl (mutex=0x5641856f2a00, file=0x564182c0e319 "../util/async.c", line=728) at ../util/qemu-thread-posix.c:149
> #4  0x00005641829532d5 in aio_context_acquire (ctx=0x5641856f29a0) at ../util/async.c:728
> #5  0x000056418279d5df in bdrv_set_aio_context_commit (opaque=0x5641856e6e50) at ../block.c:7493
> #6  0x000056418294e288 in tran_commit (tran=0x56418630bfe0) at ../util/transactions.c:87
> #7  0x000056418279d880 in bdrv_try_change_aio_context (bs=0x5641856f7130, ctx=0x56418548f810, ignore_child=0x0, errp=0x0) at ../block.c:7626
> #8  0x0000564182793f39 in bdrv_root_unref_child (child=0x5641856f47d0) at ../block.c:3242
> #9  0x00005641827be137 in blk_remove_bs (blk=0x564185709880) at ../block/block-backend.c:914
> #10 0x00005641827bd689 in blk_remove_all_bs () at ../block/block-backend.c:583
> #11 0x0000564182798699 in bdrv_close_all () at ../block.c:5117
> #12 0x000056418248a5b2 in qemu_cleanup () at ../softmmu/runstate.c:821
> #13 0x0000564182738603 in qemu_default_main () at ../softmmu/main.c:38
> #14 0x0000564182738631 in main (argc=30, argv=0x7ffd675a8a48) at ../softmmu/main.c:48
>
> (gdb) p *((QemuMutex*)0x5641856f2a00)
> $1 = {lock = {__data = {__lock = 2, __count = 2, __owner = 135952, ...
> (gdb) p *((QemuMutex*)0x564183365f00)
> $2 = {lock = {__data = {__lock = 2, __count = 0, __owner = 135944, ...

[1]:

> Thread 1 "qemu-system-x86" hit Breakpoint 5, bdrv_drain_all_end () at ../block/io.c:551
> #0  bdrv_drain_all_end () at ../block/io.c:551
> xen-project#1  0x00005569810f0376 in bdrv_graph_wrlock (bs=0x0) at ../block/graph-lock.c:156
> #2  0x00005569810bd3e0 in bdrv_replace_child_noperm (child=0x556982e2d7d0, new_bs=0x0) at ../block.c:2897
> #3  0x00005569810bdef2 in bdrv_root_unref_child (child=0x556982e2d7d0) at ../block.c:3227
> #4  0x00005569810e8137 in blk_remove_bs (blk=0x556982e42880) at ../block/block-backend.c:914
> #5  0x00005569810e7689 in blk_remove_all_bs () at ../block/block-backend.c:583
> #6  0x00005569810c2699 in bdrv_close_all () at ../block.c:5117
> #7  0x0000556980db45b2 in qemu_cleanup () at ../softmmu/runstate.c:821
> #8  0x0000556981062603 in qemu_default_main () at ../softmmu/main.c:38
> #9  0x0000556981062631 in main (argc=30, argv=0x7ffd7a82a418) at ../softmmu/main.c:48
> [Switching to Thread 0x7fe76dab2700 (LWP 103649)]
>
> Thread 3 "qemu-system-x86" hit Breakpoint 4, blk_inc_in_flight (blk=0x556982e42880) at ../block/block-backend.c:1505
> #0  blk_inc_in_flight (blk=0x556982e42880) at ../block/block-backend.c:1505
> xen-project#1  0x00005569810e8f36 in blk_wait_while_drained (blk=0x556982e42880) at ../block/block-backend.c:1312
> #2  0x00005569810e9231 in blk_co_do_pwritev_part (blk=0x556982e42880, offset=3422961664, bytes=4096, qiov=0x556983028060, qiov_offset=0, flags=0) at ../block/block-backend.c:1402
> #3  0x00005569810e9a4b in blk_aio_write_entry (opaque=0x556982e2cfa0) at ../block/block-backend.c:1628
> #4  0x000055698128038a in coroutine_trampoline (i0=-2090057872, i1=21865) at ../util/coroutine-ucontext.c:177
> #5  0x00007fe770f50d40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
> #6  0x00007ffd7a829570 in ?? ()
> #7  0x0000000000000000 in ?? ()

Signed-off-by: Fiona Ebner <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
(cherry picked from commit ca2a5e6)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 4, 2024
In pl011_get_baudrate(), when we calculate the baudrate we can
accidentally divide by zero. This happens because although (as the
specification requires) we treat UARTIBRD = 0 as invalid, we aren't
correctly limiting UARTIBRD and UARTFBRD values to the 16-bit and 6-bit
ranges the hardware allows, and so some non-zero values of UARTIBRD can
result in a zero divisor.

Enforce the correct register field widths on guest writes and on inbound
migration to avoid the division by zero.

ASAN log:
==2973125==ERROR: AddressSanitizer: FPE on unknown address 0x55f72629b348
(pc 0x55f72629b348 bp 0x7fffa24d0e00 sp 0x7fffa24d0d60 T0)
     #0 0x55f72629b348 in pl011_get_baudrate hw/char/pl011.c:255:17
     xen-project#1 0x55f726298d94 in pl011_trace_baudrate_change hw/char/pl011.c:260:33
     #2 0x55f726296fc8 in pl011_write hw/char/pl011.c:378:9

Reproducer:
cat << EOF | qemu-system-aarch64 -display \
none -machine accel=qtest, -m 512M -machine realview-pb-a8 -qtest stdio
writeq 0x1000b024 0xf8000000
EOF

Suggested-by: Peter Maydell <[email protected]>
Signed-off-by: Zheyu Ma <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 4, 2024
Commit 73064ed ("hw/nvme: flexible data placement emulation")
intorudced NVMe FDP feature to nvme-subsys and nvme-ctrl with a
single endurance group xen-project#1 supported.  This means that controller should
return proper identify data to host with Identify Endurance Group List
(CNS 19h).  But, yes, only just for the endurance group xen-project#1.  This patch
allows host applications to ask for which endurance group is available
and utilize FDP through that endurance group.

Reviewed-by: Klaus Jensen <[email protected]>
Signed-off-by: Minwoo Im <[email protected]>
Signed-off-by: Klaus Jensen <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 4, 2024
…te_asym_session

Currently, if the function fails during the key_len check, the op_code
does not have a proper value, causing virtio_crypto_free_create_session_req
not to free the memory correctly, leading to a memory leak.

By setting the op_code before performing any checks, we ensure that
virtio_crypto_free_create_session_req has the correct context to
perform cleanup operations properly, thus preventing memory leaks.

ASAN log:
==3055068==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 512 byte(s) in 1 object(s) allocated from:
    #0 0x5586a75e6ddd in malloc llvm/compiler-rt/lib/asan/asan_malloc_linux.cpp:129:3
    xen-project#1 0x7fb6b63b6738 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x5e738)
    #2 0x5586a864bbde in virtio_crypto_handle_ctrl hw/virtio/virtio-crypto.c:407:19
    #3 0x5586a94fc84c in virtio_queue_notify_vq hw/virtio/virtio.c:2277:9
    #4 0x5586a94fc0a2 in virtio_queue_host_notifier_read hw/virtio/virtio.c:3641:9

Signed-off-by: Zheyu Ma <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 4, 2024
The allocated memory to hold LBA ranges leaks in the nvme_dsm function. This
happens because the allocated memory for iocb->range is not freed in all
error handling paths.

Fix this by adding a free to ensure that the allocated memory is properly freed.

ASAN log:
==3075137==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 480 byte(s) in 6 object(s) allocated from:
    #0 0x55f1f8a0eddd in malloc llvm/compiler-rt/lib/asan/asan_malloc_linux.cpp:129:3
    xen-project#1 0x7f531e0f6738 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x5e738)
    #2 0x55f1faf1f091 in blk_aio_get block/block-backend.c:2583:12
    #3 0x55f1f945c74b in nvme_dsm hw/nvme/ctrl.c:2609:30
    #4 0x55f1f945831b in nvme_io_cmd hw/nvme/ctrl.c:4470:16
    #5 0x55f1f94561b7 in nvme_process_sq hw/nvme/ctrl.c:7039:29

Cc: [email protected]
Fixes: d7d1474 ("hw/nvme: reimplement dsm to allow cancellation")
Signed-off-by: Zheyu Ma <[email protected]>
Reviewed-by: Klaus Jensen <[email protected]>
Signed-off-by: Klaus Jensen <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 4, 2024
When the creds->username property is set we allocate memory
for it in qcrypto_tls_creds_psk_prop_set_username(), but
we never free this when the QCryptoTLSCredsPSK is destroyed.
Free the memory in finalize.

This fixes a LeakSanitizer complaint in migration-test:

$ (cd build/asan; ASAN_OPTIONS="fast_unwind_on_malloc=0" QTEST_QEMU_BINARY=./qemu-system-x86_64 ./tests/qtest/migration-test --tap -k -p /x86_64/migration/precopy/unix/tls/psk)

=================================================================
==3867512==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 5 byte(s) in 1 object(s) allocated from:
    #0 0x5624e5c99dee in malloc (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qemu-system-x86_64+0x218edee) (BuildId: a9e623fa1009a9435c0142c037cd7b8c1ad04ce3)
    xen-project#1 0x7fb199ae9738 in g_malloc debian/build/deb/../../../glib/gmem.c:128:13
    #2 0x7fb199afe583 in g_strdup debian/build/deb/../../../glib/gstrfuncs.c:361:17
    #3 0x5624e82ea919 in qcrypto_tls_creds_psk_prop_set_username /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../crypto/tlscredspsk.c:255:23
    #4 0x5624e812c6b5 in property_set_str /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qom/object.c:2277:5
    #5 0x5624e8125ce5 in object_property_set /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qom/object.c:1463:5
    #6 0x5624e8136e7c in object_set_properties_from_qdict /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qom/object_interfaces.c:55:14
    #7 0x5624e81372d2 in user_creatable_add_type /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qom/object_interfaces.c:112:5
    #8 0x5624e8137964 in user_creatable_add_qapi /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qom/object_interfaces.c:157:11
    #9 0x5624e891ba3c in qmp_object_add /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qom/qom-qmp-cmds.c:227:5
    #10 0x5624e8af9118 in qmp_marshal_object_add /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qapi/qapi-commands-qom.c:337:5
    #11 0x5624e8bd1d49 in do_qmp_dispatch_bh /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../qapi/qmp-dispatch.c:128:5
    #12 0x5624e8cb2531 in aio_bh_call /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/async.c:171:5
    #13 0x5624e8cb340c in aio_bh_poll /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/async.c:218:13
    #14 0x5624e8c0be98 in aio_dispatch /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/aio-posix.c:423:5
    #15 0x5624e8cba3ce in aio_ctx_dispatch /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/async.c:360:5
    #16 0x7fb199ae0d3a in g_main_dispatch debian/build/deb/../../../glib/gmain.c:3419:28
    #17 0x7fb199ae0d3a in g_main_context_dispatch debian/build/deb/../../../glib/gmain.c:4137:7
    #18 0x5624e8cbe1d9 in glib_pollfds_poll /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/main-loop.c:287:9
    #19 0x5624e8cbcb13 in os_host_main_loop_wait /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/main-loop.c:310:5
    #20 0x5624e8cbc6dc in main_loop_wait /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../util/main-loop.c:589:11
    #21 0x5624e6f3f917 in qemu_main_loop /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../system/runstate.c:801:9
    #22 0x5624e893379c in qemu_default_main /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../system/main.c:37:14
    #23 0x5624e89337e7 in main /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../system/main.c:48:12
    #24 0x7fb197972d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #25 0x7fb197972e3f in __libc_start_main csu/../csu/libc-start.c:392:3
    #26 0x5624e5c16fa4 in _start (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qemu-system-x86_64+0x210bfa4) (BuildId: a9e623fa1009a9435c0142c037cd7b8c1ad04ce3)

SUMMARY: AddressSanitizer: 5 byte(s) leaked in 1 allocation(s).

Cc: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Daniel P. Berrangé <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 4, 2024
In multifd_recv_setup() we allocate (among other things)
 * a MultiFDRecvData struct to multifd_recv_state::data
 * a MultiFDRecvData struct to each multfd_recv_state->params[i].data

(Then during execution we might swap these pointers around.)

But in multifd_recv_cleanup() we free multifd_recv_state->data
in multifd_recv_cleanup_state() but we don't ever free the
multifd_recv_state->params[i].data. This results in a memory
leak reported by LeakSanitizer:

(cd build/asan && \
   ASAN_OPTIONS="fast_unwind_on_malloc=0:strip_path_prefix=/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/../../" \
   QTEST_QEMU_BINARY=./qemu-system-x86_64 \
   ./tests/qtest/migration-test --tap -k -p /x86_64/migration/multifd/file/mapped-ram )
[...]
Direct leak of 72 byte(s) in 3 object(s) allocated from:
    #0 0x561cc0afcfd8 in __interceptor_calloc (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qemu-system-x86_64+0x218efd8) (BuildId: be72e086d4e47b172b0a72779972213fd9916466)
    xen-project#1 0x7f89d37acc50 in g_malloc0 debian/build/deb/../../../glib/gmem.c:161:13
    #2 0x561cc1e9c83c in multifd_recv_setup migration/multifd.c:1606:19
    #3 0x561cc1e68618 in migration_ioc_process_incoming migration/migration.c:972:9
    #4 0x561cc1e3ac59 in migration_channel_process_incoming migration/channel.c:45:9
    #5 0x561cc1e4fa0b in file_accept_incoming_migration migration/file.c:132:5
    #6 0x561cc30f2c0c in qio_channel_fd_source_dispatch io/channel-watch.c:84:12
    #7 0x7f89d37a3c43 in g_main_dispatch debian/build/deb/../../../glib/gmain.c:3419:28
    #8 0x7f89d37a3c43 in g_main_context_dispatch debian/build/deb/../../../glib/gmain.c:4137:7
    #9 0x561cc3b21659 in glib_pollfds_poll util/main-loop.c:287:9
    #10 0x561cc3b1ff93 in os_host_main_loop_wait util/main-loop.c:310:5
    #11 0x561cc3b1fb5c in main_loop_wait util/main-loop.c:589:11
    #12 0x561cc1da2917 in qemu_main_loop system/runstate.c:801:9
    #13 0x561cc3796c1c in qemu_default_main system/main.c:37:14
    #14 0x561cc3796c67 in main system/main.c:48:12
    #15 0x7f89d163bd8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #16 0x7f89d163be3f in __libc_start_main csu/../csu/libc-start.c:392:3
    #17 0x561cc0a79fa4 in _start (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qemu-system-x86_64+0x210bfa4) (BuildId: be72e086d4e47b172b0a72779972213fd9916466)

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x561cc0afcfd8 in __interceptor_calloc (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qemu-system-x86_64+0x218efd8) (BuildId: be72e086d4e47b172b0a72779972213fd9916466)
    xen-project#1 0x7f89d37acc50 in g_malloc0 debian/build/deb/../../../glib/gmem.c:161:13
    #2 0x561cc1e9bed9 in multifd_recv_setup migration/multifd.c:1588:32
    #3 0x561cc1e68618 in migration_ioc_process_incoming migration/migration.c:972:9
    #4 0x561cc1e3ac59 in migration_channel_process_incoming migration/channel.c:45:9
    #5 0x561cc1e4fa0b in file_accept_incoming_migration migration/file.c:132:5
    #6 0x561cc30f2c0c in qio_channel_fd_source_dispatch io/channel-watch.c:84:12
    #7 0x7f89d37a3c43 in g_main_dispatch debian/build/deb/../../../glib/gmain.c:3419:28
    #8 0x7f89d37a3c43 in g_main_context_dispatch debian/build/deb/../../../glib/gmain.c:4137:7
    #9 0x561cc3b21659 in glib_pollfds_poll util/main-loop.c:287:9
    #10 0x561cc3b1ff93 in os_host_main_loop_wait util/main-loop.c:310:5
    #11 0x561cc3b1fb5c in main_loop_wait util/main-loop.c:589:11
    #12 0x561cc1da2917 in qemu_main_loop system/runstate.c:801:9
    #13 0x561cc3796c1c in qemu_default_main system/main.c:37:14
    #14 0x561cc3796c67 in main system/main.c:48:12
    #15 0x7f89d163bd8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #16 0x7f89d163be3f in __libc_start_main csu/../csu/libc-start.c:392:3
    #17 0x561cc0a79fa4 in _start (/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/asan/qemu-system-x86_64+0x210bfa4) (BuildId: be72e086d4e47b172b0a72779972213fd9916466)

SUMMARY: AddressSanitizer: 96 byte(s) leaked in 4 allocation(s).

Free the params[i].data too.

Cc: [email protected]
Fixes: d117ed0 ("migration/multifd: Allow receiving pages without packets")
Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Fabiano Rosas <[email protected]>
Signed-off-by: Fabiano Rosas <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 9, 2024
We can fail the blk_insert_bs() at init_blk_migration(), leaving the
BlkMigDevState without a dirty_bitmap and BlockDriverState. Account
for the possibly missing elements when doing cleanup.

Fix the following crashes:

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555ec83ef in bdrv_release_dirty_bitmap (bitmap=0x0) at ../block/dirty-bitmap.c:359
359         BlockDriverState *bs = bitmap->bs;
 #0  0x0000555555ec83ef in bdrv_release_dirty_bitmap (bitmap=0x0) at ../block/dirty-bitmap.c:359
 xen-project#1  0x0000555555bba331 in unset_dirty_tracking () at ../migration/block.c:371
 #2  0x0000555555bbad98 in block_migration_cleanup_bmds () at ../migration/block.c:681

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555e971ff in bdrv_op_unblock (bs=0x0, op=BLOCK_OP_TYPE_BACKUP_SOURCE, reason=0x0) at ../block.c:7073
7073        QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
 #0  0x0000555555e971ff in bdrv_op_unblock (bs=0x0, op=BLOCK_OP_TYPE_BACKUP_SOURCE, reason=0x0) at ../block.c:7073
 xen-project#1  0x0000555555e9734a in bdrv_op_unblock_all (bs=0x0, reason=0x0) at ../block.c:7095
 #2  0x0000555555bbae13 in block_migration_cleanup_bmds () at ../migration/block.c:690

Signed-off-by: Fabiano Rosas <[email protected]>
Message-id: [email protected]
Signed-off-by: Stefan Hajnoczi <[email protected]>
(cherry picked from commit f187609)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 9, 2024
virtio_load() as a whole should run in coroutine context because it
reads from the migration stream and we don't want this to block.

However, it calls virtio_set_features_nocheck() and devices don't
expect their .set_features callback to run in a coroutine and therefore
call functions that may not be called in coroutine context. To fix this,
drop out of coroutine context for calling virtio_set_features_nocheck().

Without this fix, the following crash was reported:

  #0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
  xen-project#1  0x00007efc738c05d3 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
  #2  0x00007efc73873d26 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
  #3  0x00007efc738477f3 in __GI_abort () at abort.c:79
  #4  0x00007efc7384771b in __assert_fail_base (fmt=0x7efc739dbcb8 "", assertion=assertion@entry=0x560aebfbf5cf "!qemu_in_coroutine()",
     file=file@entry=0x560aebfcd2d4 "../block/graph-lock.c", line=line@entry=275, function=function@entry=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:92
  #5  0x00007efc7386ccc6 in __assert_fail (assertion=0x560aebfbf5cf "!qemu_in_coroutine()", file=0x560aebfcd2d4 "../block/graph-lock.c", line=275,
     function=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:101
  #6  0x0000560aebcd8dd6 in bdrv_register_buf ()
  #7  0x0000560aeb97ed97 in ram_block_added.llvm ()
  #8  0x0000560aebb8303f in ram_block_add.llvm ()
  #9  0x0000560aebb834fa in qemu_ram_alloc_internal.llvm ()
  #10 0x0000560aebb2ac98 in vfio_region_mmap ()
  #11 0x0000560aebb3ea0f in vfio_bars_register ()
  #12 0x0000560aebb3c628 in vfio_realize ()
  #13 0x0000560aeb90f0c2 in pci_qdev_realize ()
  #14 0x0000560aebc40305 in device_set_realized ()
  #15 0x0000560aebc48e07 in property_set_bool.llvm ()
  #16 0x0000560aebc46582 in object_property_set ()
  #17 0x0000560aebc4cd58 in object_property_set_qobject ()
  #18 0x0000560aebc46ba7 in object_property_set_bool ()
  #19 0x0000560aeb98b3ca in qdev_device_add_from_qdict ()
  #20 0x0000560aebb1fbaf in virtio_net_set_features ()
  #21 0x0000560aebb46b51 in virtio_set_features_nocheck ()
  #22 0x0000560aebb47107 in virtio_load ()
  #23 0x0000560aeb9ae7ce in vmstate_load_state ()
  #24 0x0000560aeb9d2ee9 in qemu_loadvm_state_main ()
  #25 0x0000560aeb9d45e1 in qemu_loadvm_state ()
  #26 0x0000560aeb9bc32c in process_incoming_migration_co.llvm ()
  #27 0x0000560aebeace56 in coroutine_trampoline.llvm ()

Cc: [email protected]
Buglink: https://issues.redhat.com/browse/RHEL-832
Signed-off-by: Kevin Wolf <[email protected]>
Message-ID: <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>
(cherry picked from commit 92e2e6a)
Signed-off-by: Michael Tokarev <[email protected]>
olafhering pushed a commit to olafhering/qemu-xen that referenced this issue Oct 9, 2024
Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555888630 in dpy_ui_info_supported (con=0x0) at ../ui/console.c:812
812	    return con->hw_ops->ui_info != NULL;
(gdb) bt
#0  0x0000555555888630 in dpy_ui_info_supported (con=0x0) at ../ui/console.c:812
xen-project#1  0x00005555558a44b1 in protocol_client_msg (vs=0x5555578c76c0, data=0x5555581e93f0 <incomplete sequence \373>, len=24) at ../ui/vnc.c:2585
#2  0x00005555558a19ac in vnc_client_read (vs=0x5555578c76c0) at ../ui/vnc.c:1607
#3  0x00005555558a1ac2 in vnc_client_io (ioc=0x5555581eb0e0, condition=G_IO_IN, opaque=0x5555578c76c0) at ../ui/vnc.c:1635

Fixes:
https://issues.redhat.com/browse/RHEL-2600

Signed-off-by: Marc-André Lureau <[email protected]>
Reviewed-by: Albert Esteve <[email protected]>
(cherry picked from commit 48a35e1)
Signed-off-by: Michael Tokarev <[email protected]>
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