Commit f391d6ee authored by Dan Carpenter's avatar Dan Carpenter Committed by Steve French
Browse files

cifs: Use after free in debug code 



This debug code dereferences "old_iface" after it was already freed by
the call to release_iface().  Re-order the debugging to avoid this
issue.

Fixes: b54034a7 ("cifs: during reconnect, update interface if necessary")
Cc: stable@vger.kernel.org # 5.19+
Reviewed-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 926028aa

fs/cifs/sess.c

+2 −2
Original line number Diff line number Diff line
@@ -302,14 +302,14 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server) 


	/* now drop the ref to the current iface */

	if (old_iface && iface) {

		kref_put(&old_iface->refcount, release_iface);

		cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",

			 &old_iface->sockaddr,

			 &iface->sockaddr);

	} else if (old_iface) {

		kref_put(&old_iface->refcount, release_iface);

	} else if (old_iface) {

		cifs_dbg(FYI, "releasing ref to iface: %pIS\n",

			 &old_iface->sockaddr);

		kref_put(&old_iface->refcount, release_iface);

	} else {

		WARN_ON(!iface);

		cifs_dbg(FYI, "adding new iface: %pIS\n", &iface->sockaddr);