From 04db8939c4219d15be6ecdae0ce667402d962601 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Wed, 31 May 2023 17:43:02 +0900 Subject: [PATCH] ksmbd: validate smb request protocol id This patch add the validation for smb request protocol id. If it is not one of the four ids(SMB1_PROTO_NUMBER, SMB2_PROTO_NUMBER, SMB2_TRANSFORM_PROTO_NUM, SMB2_COMPRESSION_TRANSFORM_ID), don't allow processing the request. And this will fix the following KASAN warning also. [ 13.905265] BUG: KASAN: slab-out-of-bounds in init_smb2_rsp_hdr+0x1b9/0x1f0 [ 13.905900] Read of size 16 at addr ffff888005fd2f34 by task kworker/0:2/44 ... [ 13.908553] Call Trace: [ 13.908793] [ 13.908995] dump_stack_lvl+0x33/0x50 [ 13.909369] print_report+0xcc/0x620 [ 13.910870] kasan_report+0xae/0xe0 [ 13.911519] kasan_check_range+0x35/0x1b0 [ 13.911796] init_smb2_rsp_hdr+0x1b9/0x1f0 [ 13.912492] handle_ksmbd_work+0xe5/0x820 Reported-by: Chih-Yen Chang Signed-off-by: Namjae Jeon --- smb2pdu.h | 1 + smb_common.c | 14 +++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/smb2pdu.h b/smb2pdu.h index 3c9547c91..2165a02b8 100644 --- a/smb2pdu.h +++ b/smb2pdu.h @@ -109,6 +109,7 @@ #define SMB2_PROTO_NUMBER cpu_to_le32(0x424d53fe) /* 'B''M''S' */ #define SMB2_TRANSFORM_PROTO_NUM cpu_to_le32(0x424d53fd) +#define SMB2_COMPRESSION_TRANSFORM_ID cpu_to_le32(0x424d53fc) #define SMB21_DEFAULT_IOSIZE (1024 * 1024) #define SMB3_DEFAULT_IOSIZE (4 * 1024 * 1024) diff --git a/smb_common.c b/smb_common.c index c6bd9f2b2..c57678868 100644 --- a/smb_common.c +++ b/smb_common.c @@ -194,7 +194,19 @@ int ksmbd_verify_smb_message(struct ksmbd_work *work) */ bool ksmbd_smb_request(struct ksmbd_conn *conn) { - return conn->request_buf[0] == 0; + __le32 *proto = (__le32 *)conn->request_buf; + + if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) { + pr_err_ratelimited("smb2 compression not support yet"); + return false; + } + + if (*proto != SMB1_PROTO_NUMBER && + *proto != SMB2_PROTO_NUMBER && + *proto != SMB2_TRANSFORM_PROTO_NUM) + return false; + + return true; } static bool supported_protocol(int idx)