Patch "tun_dst: Fix potential NULL dereference" has been added to the 4.3-stable tree

Patch "tun_dst: Fix potential NULL dereference" has been added to the 4.3-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tun_dst: Fix potential NULL dereference

to the 4.3-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tun_dst-fix-potential-null-dereference.patch
and it can be found in the queue-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Nov 17 14:33:46 PST 2015
From: Tobias Klauser <tklauser@distanz.ch>
Date: Wed, 4 Nov 2015 13:49:49 +0100
Subject: tun_dst: Fix potential NULL dereference

From: Tobias Klauser <tklauser@distanz.ch>

[ Upstream commit f63ce5b6fa5e9a0faf7a0e1ef2993a502878c78a ]

In tun_dst_unclone() the return value of skb_metadata_dst() is checked
for being NULL after it is dereferenced. Fix this by moving the
dereference after the NULL check.

Found by the Coverity scanner (CID 1338068).

Fixes: fc4099f17240 ("openvswitch: Fix egress tunnel info.")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/net/dst_metadata.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/include/net/dst_metadata.h
+++ b/include/net/dst_metadata.h
@@ -63,12 +63,13 @@ static inline struct metadata_dst *tun_r
 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
 {
 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
-	int md_size = md_dst->u.tun_info.options_len;
+	int md_size;
 	struct metadata_dst *new_md;
 
 	if (!md_dst)
 		return ERR_PTR(-EINVAL);
 
+	md_size = md_dst->u.tun_info.options_len;
 	new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
 	if (!new_md)
 		return ERR_PTR(-ENOMEM);


Patches currently in stable-queue which might be from tklauser@distanz.ch are

queue-4.3/tun_dst-fix-potential-null-dereference.patch