[3.13.y-ckt stable] Patch "ethtool: Use kcalloc instead of kmalloc for ethtool_get_strings" has been added to staging queue

[Kamal Mostafa]

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

    ethtool: Use kcalloc instead of kmalloc for ethtool_get_strings

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt30.

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

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 804cbb4f0366e668e46c722ae0f1374394e366af Mon Sep 17 00:00:00 2001
From: Joe Perches <joe at perches.com>
Date: Wed, 14 Oct 2015 01:09:40 -0700
Subject: ethtool: Use kcalloc instead of kmalloc for ethtool_get_strings

[ Upstream commit 077cb37fcf6f00a45f375161200b5ee0cd4e937b ]

It seems that kernel memory can leak into userspace by a
kmalloc, ethtool_get_strings, then copy_to_user sequence.

Avoid this by using kcalloc to zero fill the copied buffer.

Signed-off-by: Joe Perches <joe at perches.com>
Acked-by: Ben Hutchings <ben at decadent.org.uk>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/core/ethtool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 30071de..0b39ab6 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1080,7 +1080,7 @@ static int ethtool_get_strings(struct net_device *dev, void __user *useraddr)

 	gstrings.len = ret;

-	data = kmalloc(gstrings.len * ETH_GSTRING_LEN, GFP_USER);
+	data = kcalloc(gstrings.len, ETH_GSTRING_LEN, GFP_USER);
 	if (!data)
 		return -ENOMEM;

--
1.9.1