From mboxrd@z Thu Jan 1 00:00:00 1970 From: Basil Gunn Subject: [PATCH 1/1] ax25: Fix segfault after sock connection timeout Date: Sat, 14 Jan 2017 12:18:55 -0800 Message-ID: <20170114121855.62254455@brox.localnet> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: stable@vger.kernel.org, Jeremy McDermond , f6bvp To: Joerg Reuter , Ralf Baechle , "David S. Miller" , linux-hams@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Sender: linux-hams-owner@vger.kernel.org List-Id: netdev.vger.kernel.org The ax.25 socket connection timed out & the sock struct has been previously taken down ie. sock struct is now a NULL pointer. Checking the sock_flag causes the segfault. Check if the socket struct pointer is NULL before checking sock_flag. This segfault is seen in timed out netrom connections. Please submit to -stable. Signed-off-by: Basil Gunn --- diff --git a/net/ax25/ax25_subr.c b/net/ax25/ax25_subr.c index 4855d18..038b109 100644 --- a/net/ax25/ax25_subr.c +++ b/net/ax25/ax25_subr.c @@ -264,7 +264,7 @@ void ax25_disconnect(ax25_cb *ax25, int reason) { ax25_clear_queues(ax25); - if (!sock_flag(ax25->sk, SOCK_DESTROY)) + if (!ax25->sk || !sock_flag(ax25->sk, SOCK_DESTROY)) ax25_stop_heartbeat(ax25); ax25_stop_t1timer(ax25); ax25_stop_t2timer(ax25);