ASan global-buffer-overflow src/stb_image.h:1913 in stbi__extend_receive

[fgeek]

libsixel-global-buffer-overflow-stb_image.h-1913-stbi__extend_receive.png.zip (SHA1: 6fa73c3af3d0247b2c798a20c163d1b6331eaaef)
Tested commit: 5db717d
Credit: Henri Salo

./bin/img2sixel -o test libsixel-global-buffer-overflow-stb_image.h-1913-stbi__extend_receive.png
=================================================================
==2715==ERROR: AddressSanitizer: global-buffer-overflow on address 0x7f58d30cdcc0 at pc 0x7f58d302a1d1 bp 0x7ffd8fe8f3f0 sp 0x7ffd8fe8f3e8
READ of size 4 at 0x7f58d30cdcc0 thread T0
    #0 0x7f58d302a1d0 in stbi__extend_receive /home/hsalo/src/libsixel/src/stb_image.h:1913
    #1 0x7f58d302a1d0 in stbi__jpeg_decode_block /home/hsalo/src/libsixel/src/stb_image.h:1968
    #2 0x7f58d306a56f in stbi__parse_entropy_coded_data /home/hsalo/src/libsixel/src/stb_image.h:2733
    #3 0x7f58d306a56f in stbi__decode_jpeg_image /home/hsalo/src/libsixel/src/stb_image.h:3132
    #4 0x7f58d306a56f in load_jpeg_image /home/hsalo/src/libsixel/src/stb_image.h:3584
    #5 0x7f58d306a56f in stbi__jpeg_load /home/hsalo/src/libsixel/src/stb_image.h:3741
    #6 0x7f58d306a56f in stbi__load_main /home/hsalo/src/libsixel/src/stb_image.h:980
    #7 0x7f58d307e35c in stbi__load_and_postprocess_8bit /home/hsalo/src/libsixel/src/stb_image.h:1090
    #8 0x7f58d3082663 in load_with_builtin /home/hsalo/src/libsixel/src/loader.c:882
    #9 0x7f58d308f7f8 in sixel_helper_load_image_file /home/hsalo/src/libsixel/src/loader.c:1352
    #10 0x7f58d30b07de in sixel_encoder_encode /home/hsalo/src/libsixel/src/encoder.c:1734
    #11 0x564de83eebab in main /home/hsalo/src/libsixel/converters/img2sixel.c:457
    #12 0x7f58d22372e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #13 0x564de83eede9 in _start (/home/hsalo/builds/libsixel/5db717dfef6fa327cd4025e7352550f63d20699c/bin/img2sixel+0x2de9)

0x7f58d30cdcc0 is located 32 bytes to the left of global variable 'stbi__bmask' defined in 'stb_image.h:1844:27' (0x7f58d30cdce0) of size 68
0x7f58d30cdcc0 is located 0 bytes to the right of global variable 'stbi__jbias' defined in 'stb_image.h:1897:18' (0x7f58d30cdc80) of size 64
SUMMARY: AddressSanitizer: global-buffer-overflow /home/hsalo/src/libsixel/src/stb_image.h:1913 in stbi__extend_receive
Shadow bytes around the buggy address:
  0x0feb9a611b40: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
  0x0feb9a611b50: 00 00 00 00 f9 f9 f9 f9 00 00 00 00 00 00 00 00
  0x0feb9a611b60: 00 00 00 00 00 00 00 04 f9 f9 f9 f9 00 00 00 00
  0x0feb9a611b70: 00 00 00 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9
  0x0feb9a611b80: 00 00 00 00 00 00 00 00 00 07 f9 f9 f9 f9 f9 f9
=>0x0feb9a611b90: 00 00 00 00 00 00 00 00[f9]f9 f9 f9 00 00 00 00
  0x0feb9a611ba0: 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x0feb9a611bb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0feb9a611bc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0feb9a611bd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0feb9a611be0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==2715==ABORTING

[saitoha]

@fgeek thank you!

[fgeek]

Happy to help :)