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| author | Chih-Yen Chang <cc85nod@gmail.com> | 2023-05-06 00:01:54 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-05-16 10:26:14 -0500 |
| commit | f0a96d1aafd8964e1f9955c830a3e5cb3c60a90f (patch) | |
| tree | 4aea84317a387f1718b91152e6ef12a96bdc24fd /fs | |
| parent | 02f76c401d17e409ed45bf7887148fcc22c93c85 (diff) | |
| download | lwn-f0a96d1aafd8964e1f9955c830a3e5cb3c60a90f.tar.gz lwn-f0a96d1aafd8964e1f9955c830a3e5cb3c60a90f.zip | |
ksmbd: fix wrong UserName check in session_user
The offset of UserName is related to the address of security
buffer. To ensure the validaty of UserName, we need to compare name_off
+ name_len with secbuf_len instead of auth_msg_len.
[ 27.096243] ==================================================================
[ 27.096890] BUG: KASAN: slab-out-of-bounds in smb_strndup_from_utf16+0x188/0x350
[ 27.097609] Read of size 2 at addr ffff888005e3b542 by task kworker/0:0/7
...
[ 27.099950] Call Trace:
[ 27.100194] <TASK>
[ 27.100397] dump_stack_lvl+0x33/0x50
[ 27.100752] print_report+0xcc/0x620
[ 27.102305] kasan_report+0xae/0xe0
[ 27.103072] kasan_check_range+0x35/0x1b0
[ 27.103757] smb_strndup_from_utf16+0x188/0x350
[ 27.105474] smb2_sess_setup+0xaf8/0x19c0
[ 27.107935] handle_ksmbd_work+0x274/0x810
[ 27.108315] process_one_work+0x419/0x760
[ 27.108689] worker_thread+0x2a2/0x6f0
[ 27.109385] kthread+0x160/0x190
[ 27.110129] ret_from_fork+0x1f/0x30
[ 27.110454] </TASK>
Cc: stable@vger.kernel.org
Signed-off-by: Chih-Yen Chang <cc85nod@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ksmbd/smb2pdu.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index f317ce2461ee..717bcd20545b 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1356,7 +1356,7 @@ static struct ksmbd_user *session_user(struct ksmbd_conn *conn, struct authenticate_message *authblob; struct ksmbd_user *user; char *name; - unsigned int auth_msg_len, name_off, name_len, secbuf_len; + unsigned int name_off, name_len, secbuf_len; secbuf_len = le16_to_cpu(req->SecurityBufferLength); if (secbuf_len < sizeof(struct authenticate_message)) { @@ -1366,9 +1366,8 @@ static struct ksmbd_user *session_user(struct ksmbd_conn *conn, authblob = user_authblob(conn, req); name_off = le32_to_cpu(authblob->UserName.BufferOffset); name_len = le16_to_cpu(authblob->UserName.Length); - auth_msg_len = le16_to_cpu(req->SecurityBufferOffset) + secbuf_len; - if (auth_msg_len < (u64)name_off + name_len) + if (secbuf_len < (u64)name_off + name_len) return NULL; name = smb_strndup_from_utf16((const char *)authblob + name_off, |