From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Wed, 20 Apr 2011 01:57:15 +0000 (+0000)
Subject: can: add missing socket check in can/raw release
X-Git-Tag: firefly_0821_release~10186^2~24
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5d93d268311c91a6f47f8b1843b60788ba378e4c;p=firefly-linux-kernel-4.4.55.git

can: add missing socket check in can/raw release

commit 10022a6c66e199d8f61d9044543f38785713cbbd upstream.

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>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/can/raw.c b/net/can/raw.c
index b5e897922d32..c8241d06a5c5 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -280,7 +280,12 @@ 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);