[PATCH net v2] ip: limit use of gso_size to udp
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2018-06-19 16:47:55
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: Willem de Bruijn <willemb@google.com>
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 <redacted>
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
For net-next, I'll take a look whether ipcm(6)_cookie fields like
these can be initialized uniformly, and then this branch removed
completely.
---
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;
--
2.18.0.rc1.244.gcf134e6275-goog