From: Basil Gunn Date: Sat, 14 Jan 2017 20:18:55 +0000 (-0800) Subject: ax25: Fix segfault after sock connection timeout X-Git-Tag: firefly_0821_release~176^2~4^2~1^2~10 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4f5e54bdd052cb7b6f754d6e4ced0367b11af3ed;p=firefly-linux-kernel-4.4.55.git ax25: Fix segfault after sock connection timeout [ 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 --- diff --git a/net/ax25/ax25_subr.c b/net/ax25/ax25_subr.c index 655a7d4c96e1..983f0b5e14f1 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);