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authorChih-Yen Chang <cc85nod@gmail.com>2023-05-05 18:01:54 +0300
committerSteve French <stfrench@microsoft.com>2023-05-16 18:26:14 +0300
commitf0a96d1aafd8964e1f9955c830a3e5cb3c60a90f (patch)
tree4aea84317a387f1718b91152e6ef12a96bdc24fd
parent02f76c401d17e409ed45bf7887148fcc22c93c85 (diff)
downloadlinux-f0a96d1aafd8964e1f9955c830a3e5cb3c60a90f.tar.xz
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>
-rw-r--r--fs/ksmbd/smb2pdu.c5
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,