[PATCH] cifs: fix NULL dereference in smb2_check_message()

[Dan Carpenter]

This code sets "ses" to NULL which will lead to a NULL dereference on
the second iteration through the loop.

Fixes: 85346c17e425 ("cifs: convert list_for_each to entry variant in smb2misc.c")
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
---
 fs/cifs/smb2misc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index c6bb2ea1983b..668f77108831 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -158,11 +158,10 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr)
 		list_for_each_entry(ses, &srvr->smb_ses_list, smb_ses_list) {
 			if (ses->Suid == thdr->SessionId)
 				break;
-
-			ses = NULL;
 		}
 		spin_unlock(&cifs_tcp_ses_lock);
-		if (ses == NULL) {
+		if (list_entry_is_head(ses, &srvr->smb_ses_list,
+				       smb_ses_list)) {
 			cifs_dbg(VFS, "no decryption - session id not found\n");
 			return 1;
 		}
-- 
2.30.2