diff options
| author | Willem de Bruijn <willemb@google.com> | 2017-08-10 12:29:19 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-10 09:52:12 -0700 |
| commit | 85f1bd9a7b5a79d5baa8bf44af19658f7bf77bfa (patch) | |
| tree | dcf8a90eb6ae097aa5c962f8bec97e1ce4a5aab7 /net/ipv4 | |
| parent | 96d9703050a0036a3360ec98bb41e107c90664fe (diff) | |
| download | linux-85f1bd9a7b5a79d5baa8bf44af19658f7bf77bfa.tar.gz linux-85f1bd9a7b5a79d5baa8bf44af19658f7bf77bfa.tar.xz | |
udp: consistently apply ufo or fragmentation
When iteratively building a UDP datagram with MSG_MORE and that
datagram exceeds MTU, consistently choose UFO or fragmentation.
Once skb_is_gso, always apply ufo. Conversely, once a datagram is
split across multiple skbs, do not consider ufo.
Sendpage already maintains the first invariant, only add the second.
IPv6 does not have a sendpage implementation to modify.
A gso skb must have a partial checksum, do not follow sk_no_check_tx
in udp_send_skb.
Found by syzkaller.
Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_output.c | 8 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 2 |
2 files changed, 6 insertions, 4 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 50c74cd890bc..e153c40c2436 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -965,11 +965,12 @@ static int __ip_append_data(struct sock *sk, csummode = CHECKSUM_PARTIAL; cork->length += length; - if ((((length + (skb ? skb->len : fragheaderlen)) > mtu) || - (skb && skb_is_gso(skb))) && + if ((skb && skb_is_gso(skb)) || + (((length + (skb ? skb->len : fragheaderlen)) > mtu) && + (skb_queue_len(queue) <= 1) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO) && !dst_xfrm(&rt->dst) && - (sk->sk_type == SOCK_DGRAM) && !sk->sk_no_check_tx) { + (sk->sk_type == SOCK_DGRAM) && !sk->sk_no_check_tx)) { err = ip_ufo_append_data(sk, queue, getfrag, from, length, hh_len, fragheaderlen, transhdrlen, maxfraglen, flags); @@ -1288,6 +1289,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, return -EINVAL; if ((size + skb->len > mtu) && + (skb_queue_len(&sk->sk_write_queue) == 1) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO)) { if (skb->ip_summed != CHECKSUM_PARTIAL) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index e6276fa3750b..a7c804f73990 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -802,7 +802,7 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) if (is_udplite) /* UDP-Lite */ csum = udplite_csum(skb); - else if (sk->sk_no_check_tx) { /* UDP csum disabled */ + else if (sk->sk_no_check_tx && !skb_is_gso(skb)) { /* UDP csum off */ skb->ip_summed = CHECKSUM_NONE; goto send; |