From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Basil Gunn , "David S. Miller" Subject: [PATCH 4.4 11/20] ax25: Fix segfault after sock connection timeout Date: Thu, 2 Feb 2017 19:33:44 +0100 Message-Id: <20170202183309.509959381@linuxfoundation.org> In-Reply-To: <20170202183308.733256820@linuxfoundation.org> References: <20170202183308.733256820@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Basil Gunn [ Upstream commit 8a367e74c0120ef68c8c70d5a025648c96626dff ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ax25/ax25_subr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ax25/ax25_subr.c +++ b/net/ax25/ax25_subr.c @@ -264,7 +264,7 @@ void ax25_disconnect(ax25_cb *ax25, int { 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);