[ 3.5.y.z extended stable ] Patch "sysctl: fix null checking in bin_dn_node_address()" has been added to staging queue

[Luis Henriques]

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

    sysctl: fix null checking in bin_dn_node_address()

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 4493b61e596a74550ac99389015d3c41c32c297c Mon Sep 17 00:00:00 2001
From: Xi Wang <xi.wang at gmail.com>
Date: Wed, 27 Feb 2013 17:05:21 -0800
Subject: [PATCH] sysctl: fix null checking in bin_dn_node_address()

commit df1778be1a33edffa51d094eeda87c858ded6560 upstream.

The null check of `strchr() + 1' is broken, which is always non-null,
leading to OOB read.  Instead, check the result of strchr().

Signed-off-by: Xi Wang <xi.wang at gmail.com>
Cc: "Eric W. Biederman" <ebiederm at xmission.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 kernel/sysctl_binary.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index a650694..9f9aa32 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1194,9 +1194,10 @@ static ssize_t bin_dn_node_address(struct file *file,

 		/* Convert the decnet address to binary */
 		result = -EIO;
-		nodep = strchr(buf, '.') + 1;
+		nodep = strchr(buf, '.');
 		if (!nodep)
 			goto out;
+		++nodep;

 		area = simple_strtoul(buf, NULL, 10);
 		node = simple_strtoul(nodep, NULL, 10);
--
1.8.1.2