diff options
| author | Hyunchul Lee <hyc.lee@gmail.com> | 2022-07-28 21:58:53 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2022-07-31 23:14:32 -0500 |
| commit | 824d4f64c20093275f72fc8101394d75ff6a249e (patch) | |
| tree | db8160ad0622ad41d7b6bd5b95857c26c2ae7473 | |
| parent | ac60778b87e45576d7bfdbd6f53df902654e6f09 (diff) | |
ksmbd: prevent out of bound read for SMB2_TREE_CONNNECT
if Status is not 0 and PathLength is long,
smb_strndup_from_utf16 could make out of bound
read in smb2_tree_connnect.
This bug can lead an oops looking something like:
[ 1553.882047] BUG: KASAN: slab-out-of-bounds in smb_strndup_from_utf16+0x469/0x4c0 [ksmbd]
[ 1553.882064] Read of size 2 at addr ffff88802c4eda04 by task kworker/0:2/42805
...
[ 1553.882095] Call Trace:
[ 1553.882098] <TASK>
[ 1553.882101] dump_stack_lvl+0x49/0x5f
[ 1553.882107] print_report.cold+0x5e/0x5cf
[ 1553.882112] ? smb_strndup_from_utf16+0x469/0x4c0 [ksmbd]
[ 1553.882122] kasan_report+0xaa/0x120
[ 1553.882128] ? smb_strndup_from_utf16+0x469/0x4c0 [ksmbd]
[ 1553.882139] __asan_report_load_n_noabort+0xf/0x20
[ 1553.882143] smb_strndup_from_utf16+0x469/0x4c0 [ksmbd]
[ 1553.882155] ? smb_strtoUTF16+0x3b0/0x3b0 [ksmbd]
[ 1553.882166] ? __kmalloc_node+0x185/0x430
[ 1553.882171] smb2_tree_connect+0x140/0xab0 [ksmbd]
[ 1553.882185] handle_ksmbd_work+0x30e/0x1020 [ksmbd]
[ 1553.882197] process_one_work+0x778/0x11c0
[ 1553.882201] ? _raw_spin_lock_irq+0x8e/0xe0
[ 1553.882206] worker_thread+0x544/0x1180
[ 1553.882209] ? __cpuidle_text_end+0x4/0x4
[ 1553.882214] kthread+0x282/0x320
[ 1553.882218] ? process_one_work+0x11c0/0x11c0
[ 1553.882221] ? kthread_complete_and_exit+0x30/0x30
[ 1553.882225] ret_from_fork+0x1f/0x30
[ 1553.882231] </TASK>
There is no need to check error request validation in server.
This check allow invalid requests not to validate message.
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17818
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/ksmbd/smb2misc.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index aa1e663d9deb..6e25ace36568 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -90,11 +90,6 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, *off = 0; *len = 0; - /* error reqeusts do not have data area */ - if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED && - (((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2_LE) - return ret; - /* * Following commands have data areas so we have to get the location * of the data buffer offset and data buffer length for the particular |