diff options
| author | Willem de Bruijn <willemb@google.com> | 2017-08-10 16:29:19 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-13 02:31:22 (GMT) |
| commit | 33dc6a6a85f1d6ce71e7056d009b8a5fcbf10f70 (patch) | |
| tree | 068090a8c89d794c6d41dfd2f2daff1a6649d48e | |
| parent | 4688f042599f8eabe45713f7d5e88a4da5a89765 (diff) | |
| download | linux-33dc6a6a85f1d6ce71e7056d009b8a5fcbf10f70.tar.xz | |
udp: consistently apply ufo or fragmentation
[ Upstream commit 85f1bd9a7b5a79d5baa8bf44af19658f7bf77bfa ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/ip_output.c | 7 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 2 | ||||
| -rw-r--r-- | net/ipv6/ip6_output.c | 7 |
3 files changed, 10 insertions, 6 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index e5c1dbe..2c3c1a2 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -936,10 +936,12 @@ static int __ip_append_data(struct sock *sk, csummode = CHECKSUM_PARTIAL; cork->length += length; - if (((length > mtu) || (skb && skb_is_gso(skb))) && + if ((skb && skb_is_gso(skb)) || + ((length > mtu) && + (skb_queue_len(queue) <= 1) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && - (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); @@ -1255,6 +1257,7 @@ 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 5bab6c3..4363b1e 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -813,7 +813,7 @@ 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; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index efe811c..e0236e9 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1372,11 +1372,12 @@ emsgsize: */ cork->length += length; - if ((((length + fragheaderlen) > mtu) || - (skb && skb_is_gso(skb))) && + if ((skb && skb_is_gso(skb)) || + (((length + fragheaderlen) > mtu) && + (skb_queue_len(queue) <= 1) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && - (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) { + (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk))) { err = ip6_ufo_append_data(sk, queue, getfrag, from, length, hh_len, fragheaderlen, exthdrlen, transhdrlen, mtu, flags, fl6); |