[PATCH 3.16 16/55] vxlan: fix incorrect initializer in union vxlan_addr

[Greg Kroah-Hartman]

3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gerhard Stenzel <gstenzel@xxxxxxxxxxxxxxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/vxlan.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1325,7 +1325,7 @@ static int arp_reduce(struct net_device
 	} 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);
@@ -1486,7 +1486,7 @@ static int neigh_reduce(struct net_devic
 	} 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);
@@ -1519,7 +1519,7 @@ static bool route_shortcircuit(struct ne
 		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);
@@ -1540,7 +1540,7 @@ static bool route_shortcircuit(struct ne
 		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);


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