ip: limit use of gso_size to udp

The ipcm(6)_cookie field gso_size is set only in the udp path. The ip
layer copies this to cork only if sk_type is SOCK_DGRAM. This check
proved too permissive. Ping and l2tp sockets have the same type.

Limit to sockets of type SOCK_DGRAM and protocol IPPROTO_UDP to
exclude ping sockets.

v1 -> v2
- remove irrelevant whitespace changes

Fixes: bec1f6f697 ("udp: generate gso with UDP_SEGMENT")
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Willem de Bruijn 2018-06-19 12:47:52 -04:00 committed by David S. Miller
parent b6cfffa7ad
commit 9887cba199
2 changed files with 4 additions and 2 deletions

View File

@ -1145,7 +1145,8 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
cork->fragsize = ip_sk_use_pmtu(sk) ?
dst_mtu(&rt->dst) : rt->dst.dev->mtu;
cork->gso_size = sk->sk_type == SOCK_DGRAM ? ipc->gso_size : 0;
cork->gso_size = sk->sk_type == SOCK_DGRAM &&
sk->sk_protocol == IPPROTO_UDP ? ipc->gso_size : 0;
cork->dst = &rt->dst;
cork->length = 0;
cork->ttl = ipc->ttl;

View File

@ -1219,7 +1219,8 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
if (mtu < IPV6_MIN_MTU)
return -EINVAL;
cork->base.fragsize = mtu;
cork->base.gso_size = sk->sk_type == SOCK_DGRAM ? ipc6->gso_size : 0;
cork->base.gso_size = sk->sk_type == SOCK_DGRAM &&
sk->sk_protocol == IPPROTO_UDP ? ipc6->gso_size : 0;
if (dst_allfrag(xfrm_dst_path(&rt->dst)))
cork->base.flags |= IPCORK_ALLFRAG;