From 6e601a53566d84e1ffd25e7b6fe0b6894ffd79c0 Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli@googlemail.com>
Date: Sat, 23 Feb 2013 01:13:47 +0000
Subject: sock_diag: Fix out-of-bounds access to sock_diag_handlers[]

Userland can send a netlink message requesting SOCK_DIAG_BY_FAMILY
with a family greater or equal then AF_MAX -- the array size of
sock_diag_handlers[]. The current code does not test for this
condition therefore is vulnerable to an out-of-bound access opening
doors for a privilege escalation.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -126,6 +126,9 @@ static int __sock_diag_rcv_msg(struct sk
 	if (nlmsg_len(nlh) < sizeof(*req))
 		return -EINVAL;
 
+	if (req->sdiag_family >= AF_MAX)
+		return -EINVAL;
+
 	hndl = sock_diag_lock_handler(req->sdiag_family);
 	if (hndl == NULL)
 		err = -ENOENT;