vti6: better validate user provided tunnel names

BugLink: http://bugs.launchpad.net/bugs/1763366
[ Upstream commit 537b361fbcbcc3cd6fe2bb47069fd292b9256d16 ]

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

Fixes: ed1efb2aefbb ("ipv6: Add support for IPsec virtual tunnel interfaces")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 8c184f84f35334ebbc97cf3f249c5ae71ad6826d..15c51686e0764aa9f6ac6d2de8f29a69c475e6f9 100644 (file)
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -212,10 +212,13 @@ static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p
        char name[IFNAMSIZ];
        int err;
 
-       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, "ip6_vti%%d");
+       }
 
        dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
        if (!dev)