[PATCH net 5/6] ip6_tunnel: better validate user provided tunnel names

[Eric Dumazet]

Use valid_name() to make sure user does not provide illegal
device name.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <eduma...@google.com>
---
 net/ipv6/ip6_tunnel.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 
df4c29f7d59f030729b1158b809a10f4115d4bbf..da66aaac51cecbf933827c8842e61a8cbb4d274f
 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -297,13 +297,16 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, 
struct __ip6_tnl_parm *p)
        struct net_device *dev;
        struct ip6_tnl *t;
        char name[IFNAMSIZ];
-       int err = -ENOMEM;
+       int err = -E2BIG;
 
-       if (p->name[0])
+       if (p->name[0]) {
+               if (!dev_valid_name(p->name))
+                       goto failed;
                strlcpy(name, p->name, IFNAMSIZ);
-       else
+       } else {
                sprintf(name, "ip6tnl%%d");
-
+       }
+       err = -ENOMEM;
        dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
                           ip6_tnl_dev_setup);
        if (!dev)
-- 
2.17.0.484.g0c8726318c-goog