[3.13.y.z extended stable] Patch "vxlan: fix incorrect initializer in union vxlan_addr" has been added to staging queue

[Kamal Mostafa]

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

    vxlan: fix incorrect initializer in union vxlan_addr

to the linux-3.13.y-queue branch of the 3.13.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-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.11.

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.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From a1cc6e72c4daf544b2cef57e2629e688b5f26504 Mon Sep 17 00:00:00 2001
From: Gerhard Stenzel <gstenzel at linux.vnet.ibm.com>
Date: Fri, 22 Aug 2014 21:34:16 +0200
Subject: vxlan: fix incorrect initializer in union vxlan_addr

[ Upstream commit a45e92a599e77ee6a850eabdd0141633fde03915 ]

The first initializer in the following

        union vxlan_addr ipa = {
            .sin.sin_addr.s_addr = tip,
            .sa.sa_family = AF_INET,
        };

is optimised away by the compiler, due to the second initializer,
therefore initialising .sin.sin_addr.s_addr always to 0.
This results in netlink messages indicating a L3 miss never contain the
missed IP address. This was observed with GCC 4.8 and 4.9. I do not know about previous versions.
The problem affects user space programs relying on an IP address being
sent as part of a netlink message indicating a L3 miss.

Changing
            .sa.sa_family = AF_INET,
to
            .sin.sin_family = AF_INET,
fixes the problem.

Signed-off-by: Gerhard Stenzel <gerhard.stenzel at de.ibm.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/vxlan.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 7e748a1..5543eb1 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1224,7 +1224,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb)
 	} else if (vxlan->flags & VXLAN_F_L3MISS) {
 		union vxlan_addr ipa = {
 			.sin.sin_addr.s_addr = tip,
-			.sa.sa_family = AF_INET,
+			.sin.sin_family = AF_INET,
 		};

 		vxlan_ip_miss(dev, &ipa);
@@ -1385,7 +1385,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb)
 	} else if (vxlan->flags & VXLAN_F_L3MISS) {
 		union vxlan_addr ipa = {
 			.sin6.sin6_addr = msg->target,
-			.sa.sa_family = AF_INET6,
+			.sin6.sin6_family = AF_INET6,
 		};

 		vxlan_ip_miss(dev, &ipa);
@@ -1418,7 +1418,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
 		if (!n && (vxlan->flags & VXLAN_F_L3MISS)) {
 			union vxlan_addr ipa = {
 				.sin.sin_addr.s_addr = pip->daddr,
-				.sa.sa_family = AF_INET,
+				.sin.sin_family = AF_INET,
 			};

 			vxlan_ip_miss(dev, &ipa);
@@ -1439,7 +1439,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
 		if (!n && (vxlan->flags & VXLAN_F_L3MISS)) {
 			union vxlan_addr ipa = {
 				.sin6.sin6_addr = pip6->daddr,
-				.sa.sa_family = AF_INET6,
+				.sin6.sin6_family = AF_INET6,
 			};

 			vxlan_ip_miss(dev, &ipa);
--
1.9.1