[ 3.5.y.z extended stable ] Patch "sock_diag: Fix out-of-bounds access to sock_diag_handlers[]" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    sock_diag: Fix out-of-bounds access to sock_diag_handlers[]

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From e83c00b5daeaeef5635926d9e907f100f1bfa419 Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli at googlemail.com>
Date: Sat, 23 Feb 2013 01:13:47 +0000
Subject: [PATCH] sock_diag: Fix out-of-bounds access to sock_diag_handlers[]

commit 6e601a53566d84e1ffd25e7b6fe0b6894ffd79c0 upstream.

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 at googlemail.com>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/core/sock_diag.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index 5fd1467..964a92c 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -126,6 +126,9 @@ static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	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;
--
1.8.1.2