Re: [PATCH] can: check for null sk before deferencing it via the call to sock_net
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: 2017-09-08 17:46:28
Also in:
kernel-janitors, lkml, netdev
On 09/08/2017 05:02 PM, Colin King wrote:
From: Colin Ian King <redacted>
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 <redacted>Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Thanks Collin!
quoted hunk ↗ jump to hunk
--- 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..a3791674b8ce 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. */