From b20e7bbfc7a15a4182730f0936433145992b4b06 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 21 Mar 2011 18:18:00 -0700
Subject: [PATCH] net/appletalk: fix atalk_release use after free
The BKL removal in appletalk introduced a use-after-free problem,
where atalk_destroy_socket frees a sock, but we still release
the socket lock on it.
An easy fix is to take an extra reference on the sock and sock_put
it when returning from atalk_release.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/appletalk/ddp.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 3d4f4b043406..206e771e82d1 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1051,6 +1051,7 @@ static int atalk_release(struct socket *sock)
{
struct sock *sk = sock->sk;
+ sock_hold(sk);
lock_sock(sk);
if (sk) {
sock_orphan(sk);
@@ -1058,6 +1059,8 @@ static int atalk_release(struct socket *sock)
atalk_destroy_socket(sk);
}
release_sock(sk);
+ sock_put(sk);
+
return 0;
}
--
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