From: stephen hemminger <shemminger@vyatta.com>
Date: Tue, 9 Oct 2012 20:35:53 +0000 (+0000)
Subject: vxlan: fix oops when give unknown ifindex
X-Git-Tag: firefly_0821_release~3680^2~1829^2~17
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=34e02aa1fb0886d8e92ab00e3dc17d631487f92d;p=firefly-linux-kernel-4.4.55.git

vxlan: fix oops when give unknown ifindex

If vxlan is created and the ifindex is passed; there are two cases which
are incorrectly handled by the existing code. The ifindex could be zero
(i.e. no device) or there could be no device with that ifindex.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 763061d97921..607976c00162 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1090,14 +1090,18 @@ static int vxlan_newlink(struct net *net, struct net_device *dev,
 	if (data[IFLA_VXLAN_LOCAL])
 		vxlan->saddr = nla_get_be32(data[IFLA_VXLAN_LOCAL]);
 
-	if (data[IFLA_VXLAN_LINK]) {
-		vxlan->link = nla_get_u32(data[IFLA_VXLAN_LINK]);
+	if (data[IFLA_VXLAN_LINK] &&
+	    (vxlan->link = nla_get_u32(data[IFLA_VXLAN_LINK]))) {
+		struct net_device *lowerdev
+			 = __dev_get_by_index(net, vxlan->link);
+
+		if (!lowerdev) {
+			pr_info("ifindex %d does not exist\n", vxlan->link);
+			return -ENODEV;
+		}
 
-		if (!tb[IFLA_MTU]) {
-			struct net_device *lowerdev;
-			lowerdev = __dev_get_by_index(net, vxlan->link);
+		if (!tb[IFLA_MTU])
 			dev->mtu = lowerdev->mtu - VXLAN_HEADROOM;
-		}
 	}
 
 	if (data[IFLA_VXLAN_TOS])