can: bcm: check for null sk before deferencing it via the call to soc…

…k_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: 384317e ("can: network namespace support for CAN_BCM protocol") Signed-off-by: Colin Ian King <[email protected]> Acked-by: Oliver Hartkopp <[email protected]> Signed-off-by: Marc Kleine-Budde <[email protected]>
sughodke · Oct 19, 2017 · 62c0464 · 62c0464
1 parent fb5b91d
commit 62c0464
Showing 1 changed file with 3 additions and 2 deletions.
diff --git 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. */