From: David S. Miller <davem@davemloft.net>
Date: Fri, 1 Apr 2011 01:59:10 +0000 (-0700)
Subject: appletalk: Fix OOPS in atalk_release().
X-Git-Tag: firefly_0821_release~7613^2~1666^2~25
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=c100c8f4c3c6f2a407bdbaaad2c4f1062e6a473a;p=firefly-linux-kernel-4.4.55.git

appletalk: Fix OOPS in atalk_release().

Commit 60d9f461a20ba59219fdcdc30cbf8e3a4ad3f625 ("appletalk: remove
the BKL") added a dereference of "sk" before checking for NULL in
atalk_release().

Guard the code block completely, rather than partially, with the
NULL check.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 206e771e82d1..956a5302002a 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1051,16 +1051,17 @@ static int atalk_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 
-	sock_hold(sk);
-	lock_sock(sk);
 	if (sk) {
+		sock_hold(sk);
+		lock_sock(sk);
+
 		sock_orphan(sk);
 		sock->sk = NULL;
 		atalk_destroy_socket(sk);
-	}
-	release_sock(sk);
-	sock_put(sk);
 
+		release_sock(sk);
+		sock_put(sk);
+	}
 	return 0;
 }