diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2023-06-15 15:04:40 +0200 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-06-17 04:04:36 +0200 |
| commit | 5fe7f7b78290638806211046a99f031ff26164e1 (patch) | |
| tree | 47dc31e0037b34c27a703f4ab185475cf123006d /fs/smb | |
| parent | ksmbd: add mnt_want_write to ksmbd vfs functions (diff) | |
| download | linux-5fe7f7b78290638806211046a99f031ff26164e1.tar.xz linux-5fe7f7b78290638806211046a99f031ff26164e1.zip | |
ksmbd: fix out-of-bound read in smb2_write
ksmbd_smb2_check_message doesn't validate hdr->NextCommand. If
->NextCommand is bigger than Offset + Length of smb2 write, It will
allow oversized smb2 write length. It will cause OOB read in smb2_write.
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21164
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb')
| -rw-r--r-- | fs/smb/server/smb2misc.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c index 57749f41b991..33b7e6c4ceff 100644 --- a/fs/smb/server/smb2misc.c +++ b/fs/smb/server/smb2misc.c @@ -351,10 +351,16 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work) int command; __u32 clc_len; /* calculated length */ __u32 len = get_rfc1002_len(work->request_buf); - __u32 req_struct_size; + __u32 req_struct_size, next_cmd = le32_to_cpu(hdr->NextCommand); - if (le32_to_cpu(hdr->NextCommand) > 0) - len = le32_to_cpu(hdr->NextCommand); + if ((u64)work->next_smb2_rcv_hdr_off + next_cmd > len) { + pr_err("next command(%u) offset exceeds smb msg size\n", + next_cmd); + return 1; + } + + if (next_cmd > 0) + len = next_cmd; else if (work->next_smb2_rcv_hdr_off) len -= work->next_smb2_rcv_hdr_off; |