From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Tue, 27 Jun 2017 12:42:43 +0000 (+0200)
Subject: vxlan: fix incorrect nlattr access in MTU check
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=019b13ae85260cfab9d7ccb6ca58f094d18a24fd;p=openwrt%2Fstaging%2Fblogic.git

vxlan: fix incorrect nlattr access in MTU check

The access to the wrong variable could lead to a NULL dereference and
possibly other invalid memory reads in vxlan newlink/changelink requests
with a IFLA_MTU attribute.

Fixes: a985343ba906 "vxlan: refactor verification and application of configuration"
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 0dafd8e6c665..fd0ff97e3d81 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2727,7 +2727,7 @@ static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
 	}
 
 	if (tb[IFLA_MTU]) {
-		u32 mtu = nla_get_u32(data[IFLA_MTU]);
+		u32 mtu = nla_get_u32(tb[IFLA_MTU]);
 
 		if (mtu < ETH_MIN_MTU || mtu > ETH_MAX_MTU)
 			return -EINVAL;