Commit 33dc6a6a authored by Willem de Bruijn's avatar Willem de Bruijn Committed by Greg Kroah-Hartman

udp: consistently apply ufo or fragmentation


[ Upstream commit 85f1bd9a ]

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: e89e9cf5 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4688f042
...@@ -936,10 +936,12 @@ static int __ip_append_data(struct sock *sk, ...@@ -936,10 +936,12 @@ static int __ip_append_data(struct sock *sk,
csummode = CHECKSUM_PARTIAL; csummode = CHECKSUM_PARTIAL;
cork->length += length; 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) && (sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && (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, err = ip_ufo_append_data(sk, queue, getfrag, from, length,
hh_len, fragheaderlen, transhdrlen, hh_len, fragheaderlen, transhdrlen,
maxfraglen, flags); maxfraglen, flags);
...@@ -1255,6 +1257,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, ...@@ -1255,6 +1257,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
return -EINVAL; return -EINVAL;
if ((size + skb->len > mtu) && if ((size + skb->len > mtu) &&
(skb_queue_len(&sk->sk_write_queue) == 1) &&
(sk->sk_protocol == IPPROTO_UDP) && (sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO)) { (rt->dst.dev->features & NETIF_F_UFO)) {
if (skb->ip_summed != CHECKSUM_PARTIAL) if (skb->ip_summed != CHECKSUM_PARTIAL)
......
...@@ -813,7 +813,7 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) ...@@ -813,7 +813,7 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
if (is_udplite) /* UDP-Lite */ if (is_udplite) /* UDP-Lite */
csum = udplite_csum(skb); 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; skb->ip_summed = CHECKSUM_NONE;
goto send; goto send;
......
...@@ -1372,11 +1372,12 @@ static int __ip6_append_data(struct sock *sk, ...@@ -1372,11 +1372,12 @@ static int __ip6_append_data(struct sock *sk,
*/ */
cork->length += length; cork->length += length;
if ((((length + fragheaderlen) > mtu) || if ((skb && skb_is_gso(skb)) ||
(skb && skb_is_gso(skb))) && (((length + fragheaderlen) > mtu) &&
(skb_queue_len(queue) <= 1) &&
(sk->sk_protocol == IPPROTO_UDP) && (sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && (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, err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
hh_len, fragheaderlen, exthdrlen, hh_len, fragheaderlen, exthdrlen,
transhdrlen, mtu, flags, fl6); transhdrlen, mtu, flags, fl6);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment