From 361182308766a265b6c521879b34302617a8c209 Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Mon, 9 Nov 2020 07:54:49 +0100 Subject: [PATCH] net/x25: Fix null-ptr-deref in x25_connect This fixes a regression for blocking connects introduced by commit 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect"). The x25->neighbour is already set to "NULL" by x25_disconnect() now, while a blocking connect is waiting in x25_wait_for_connection_establishment(). Therefore x25->neighbour must not be accessed here again and x25->state is also already set to X25_STATE_0 by x25_disconnect(). Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Signed-off-by: Martin Schiller Reviewed-by: Xie He Link: https://lore.kernel.org/r/20201109065449.9014-1-ms@dev.tdt.de Signed-off-by: Jakub Kicinski --- net/x25/af_x25.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 0bbb283f23c9..046d3fee66a9 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -825,7 +825,7 @@ static int x25_connect(struct socket *sock, struct sockaddr *uaddr, sock->state = SS_CONNECTED; rc = 0; out_put_neigh: - if (rc) { + if (rc && x25->neighbour) { read_lock_bh(&x25_list_lock); x25_neigh_put(x25->neighbour); x25->neighbour = NULL;