Commit d61746b2 authored Sep 22, 2014 by Steffen Klassert Committed by David S. Miller Sep 26, 2014

ip_tunnel: Don't allow to add the same tunnel multiple times.



When we try to add an already existing tunnel, we don't return
an error. Instead we continue and call ip_tunnel_update().
This means that we can change existing tunnels by adding
the same tunnel multiple times. It is even possible to change
the tunnel endpoints of the fallback device.

We fix this by returning an error if we try to add an existing
tunnel.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent b94d525e

net/ipv4/ip_tunnel.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -764,11 +764,16 @@ int ip_tunnel_ioctl(struct net_device dev, struct ip_tunnel_parm p, int cmd)

		t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);

		if (!t && (cmd == SIOCADDTUNNEL)) {
		if (cmd == SIOCADDTUNNEL) {
		if (!t) {
		t = ip_tunnel_create(net, itn, p);
		err = PTR_ERR_OR_ZERO(t);
		break;
		}

		err = -EEXIST;
		break;
		}
		if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
		if (t != NULL) {
		if (t->dev != dev) {

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