From 9887cba19978a5f288100ef90a37684cc8d5e0a6 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Tue, 19 Jun 2018 12:47:52 -0400 Subject: [PATCH] ip: limit use of gso_size to udp MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT") Reported-by: Maciej Żenczykowski Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/ipv4/ip_output.c | 3 ++- net/ipv6/ip6_output.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index af5a830ff6ad..b3308e9d9762 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -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; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 021e5aef6ba3..a14fb4fcdf18 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -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; -- 2.39.5