From: Colin Ian King Date: Fri, 8 Sep 2017 15:02:35 +0000 (+0100) Subject: can: bcm: check for null sk before deferencing it via the call to sock_net X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=62c04647c6f44fa3d5d0c077133da0aa1cbbc34c;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git can: bcm: check for null sk before deferencing it via the call to sock_net 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 --- 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. */