[PATCH net 0/3] ipv6: Return an error when adding an already existing tunnel

[PATCH net 0/3] ipv6: Return an error when adding an already existing tunnel

[Steffen Klassert]

The ipv6 tunnel locate functions should not return an existing
tunnel if create is true. Otherwise it is possible to add the
same tunnel multiple times without getting an error.

All our ipv6 tunnels have this bug from the very beginning.
Only the sit tunnel was fixed some years ago with:

commit 8db99e57175 ("sit: Fail to create tunnel, if it already exists").

This patchset fixes the remaining ipv6 tunnels.

[PATCH net 1/3] ip6_tunnel: Return an error when adding an existing tunnel.

[Steffen Klassert]

ip6_tnl_locate() should not return an existing tunnel if
create is true. Otherwise it is possible to add the same
tunnel multiple times without getting an error.

So return NULL if the tunnel that should be created already
exists.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv6/ip6_tunnel.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index f9de5a6..69a84b4 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -364,8 +364,12 @@ static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 	     (t = rtnl_dereference(*tp)) != NULL;
 	     tp = &t->next) {
 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
-		    ipv6_addr_equal(remote, &t->parms.raddr))
+		    ipv6_addr_equal(remote, &t->parms.raddr)) {
+			if (create)
+				return NULL;
+
 			return t;
+		}
 	}
 	if (!create)
 		return NULL;
-- 
1.9.1

[PATCH net 2/3] ip6_vti: Return an error when adding an existing tunnel.

[Steffen Klassert]

vti6_locate() should not return an existing tunnel if
create is true. Otherwise it is possible to add the same
tunnel multiple times without getting an error.

So return NULL if the tunnel that should be created already
exists.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv6/ip6_vti.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 7f52fd9..5833a22 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -253,8 +253,12 @@ static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
 	     (t = rtnl_dereference(*tp)) != NULL;
 	     tp = &t->next) {
 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
-		    ipv6_addr_equal(remote, &t->parms.raddr))
+		    ipv6_addr_equal(remote, &t->parms.raddr)) {
+			if (create)
+				return NULL;
+
 			return t;
+		}
 	}
 	if (!create)
 		return NULL;
-- 
1.9.1

[PATCH net 3/3] ip6_gre: Return an error when adding an existing tunnel.

[Steffen Klassert]

ip6gre_tunnel_locate() should not return an existing tunnel if
create is true. Otherwise it is possible to add the same
tunnel multiple times without getting an error.

So return NULL if the tunnel that should be created already
exists.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv6/ip6_gre.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 5f19dfb..2e5a882 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -314,6 +314,8 @@ static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 
 	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
+	if (t && create)
+		return NULL;
 	if (t || !create)
 		return t;
 
-- 
1.9.1

Re: [PATCH net 0/3] ipv6: Return an error when adding an already existing tunnel

[David Miller]

From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Mon, 22 Sep 2014 10:07:23 +0200

> The ipv6 tunnel locate functions should not return an existing
> tunnel if create is true. Otherwise it is possible to add the
> same tunnel multiple times without getting an error.
> 
> All our ipv6 tunnels have this bug from the very beginning.
> Only the sit tunnel was fixed some years ago with:
> 
> commit 8db99e57175 ("sit: Fail to create tunnel, if it already exists").
> 
> This patchset fixes the remaining ipv6 tunnels.

Series applied and queued up for -stable, thanks.