cifs: fix incorrect check for null pointer in header_assemble

commit 9ed38fd4a15417cac83967360cf20b853bfab9b6 upstream.

Although very unlikely that the tlink pointer would be null in this case,
get_next_mid function can in theory return null (but not an error)
so need to check for null (not for IS_ERR, which can not be returned
here).

Address warning:

        fs/smbfs_client/connect.c:2392 cifs_match_super()
        warn: 'tlink' isn't an ERR_PTR

Pointed out by Dan Carpenter via smatch code analysis tool

CC: stable@vger.kernel.org
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Steve French 2021-09-23 19:18:37 -05:00 committed by Greg Kroah-Hartman
parent 5940e22528
commit 93028da5e9

View File

@ -3504,9 +3504,10 @@ cifs_match_super(struct super_block *sb, void *data)
spin_lock(&cifs_tcp_ses_lock);
cifs_sb = CIFS_SB(sb);
tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
if (IS_ERR(tlink)) {
if (tlink == NULL) {
/* can not match superblock if tlink were ever null */
spin_unlock(&cifs_tcp_ses_lock);
return rc;
return 0;
}
tcon = tlink_tcon(tlink);
ses = tcon->ses;