[PATCH 3.16 112/366] vti6: better validate user provided tunnel names

Ben Hutchings
2018-10-14T23:24:56Z

From: Eric Dumazet <edumazet@google.com>

commit 537b361fbcbcc3cd6fe2bb47069fd292b9256d16 upstream.

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: Ben Hutchings <ben@decadent.org.uk>
---
net/ipv6/ip6_vti.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -195,10 +195,13 @@ static struct ip6_tnl *vti6_tnl_create(s
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, vti6_dev_setup);
if (dev == NULL)