can: add missing socket check in can/raw release

v2: added space after 'if' according code style.

We can get here with a NULL socket argument passed from userspace,
so we need to handle it accordingly.

Thanks to Dave Jones pointing at this issue in net/can/bcm.c

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
index 649acfa7c70a..0eb39a7fdf64 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -305,7 +305,12 @@ static int raw_init(struct sock *sk)
 static int raw_release(struct socket *sock)
 {
         struct sock *sk = sock->sk;
-        struct raw_sock *ro = raw_sk(sk);
+        struct raw_sock *ro;
+
+        if (!sk)
+                return 0;
+
+        ro = raw_sk(sk);
 
         unregister_netdevice_notifier(&ro->notifier);