Commit 8b06b0f1 authored Sep 23, 2021 by Steve French Committed by Greg Kroah-Hartman Sep 30, 2021

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>

parent b1f6efa2

fs/cifs/connect.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -3691,9 +3691,10 @@ 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;