From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: [PATCH 07/11] can: bcm: check for null sk before deferencing it via the call to sock_net Date: Thu, 19 Oct 2017 13:19:41 +0200 Message-ID: <20171019111945.13580-8-mkl@pengutronix.de> References: <20171019111945.13580-1-mkl@pengutronix.de> Return-path: In-Reply-To: <20171019111945.13580-1-mkl@pengutronix.de> Sender: netdev-owner@vger.kernel.org To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, Colin Ian King , Marc Kleine-Budde List-Id: linux-can.vger.kernel.org From: Colin Ian King The assignment of net via call sock_net will dereference sk. This is performed before a sanity null check on sk, so there could be a potential null dereference on the sock_net call if sk is null. Fix this by assigning net after the sk null check. Also replace the sk == NULL with the more usual !sk idiom. Detected by CoverityScan CID#1431862 ("Dereference before null check") Fixes: 384317ef4187 ("can: network namespace support for CAN_BCM protocol") Signed-off-by: Colin Ian King Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- net/can/bcm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/can/bcm.c b/net/can/bcm.c index 47a8748d953a..13690334efa3 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -1493,13 +1493,14 @@ static int bcm_init(struct sock *sk) static int bcm_release(struct socket *sock) { struct sock *sk = sock->sk; - struct net *net = sock_net(sk); + struct net *net; struct bcm_sock *bo; struct bcm_op *op, *next; - if (sk == NULL) + if (!sk) return 0; + net = sock_net(sk); bo = bcm_sk(sk); /* remove bcm_ops, timer, rx_unregister(), etc. */ -- 2.14.2