From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oliver Hartkopp <socketcan@hartkopp.net>
Subject: can: add missing socket check in can/raw release.
Date: Wed, 20 Apr 2011 13:46:40 +0200
Message-ID: <4DAEC7A0.1090103@hartkopp.net>
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Cc: netdev@vger.kernel.org, Dave Jones <davej@redhat.com>
To: David Miller <davem@davemloft.net>
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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>

---

diff --git a/net/can/raw.c b/net/can/raw.c
index 649acfa..8f215e6 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);