From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Andrey Konovalov <andreyknvl@google.com>,
Willem de Bruijn <willemb@google.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 3.18 8/9] udp: consistently apply ufo or fragmentation
Date: Fri, 11 Aug 2017 15:02:51 -0700 [thread overview]
Message-ID: <20170811220246.138619329@linuxfoundation.org> (raw)
In-Reply-To: <20170811220245.783367624@linuxfoundation.org>
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Willem de Bruijn <willemb@google.com>
[ 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.
[gregkh - tweaks for 3.18 for ipv6, hopefully they are correct...]
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>
---
net/ipv4/ip_output.c | 7 +++++--
net/ipv4/udp.c | 2 +-
net/ipv6/ip6_output.c | 7 ++++---
3 files changed, 10 insertions(+), 6 deletions(-)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -888,10 +888,12 @@ static int __ip_append_data(struct sock
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_type == SOCK_DGRAM))) {
err = ip_ufo_append_data(sk, queue, getfrag, from, length,
hh_len, fragheaderlen, transhdrlen,
maxfraglen, flags);
@@ -1207,6 +1209,7 @@ ssize_t ip_append_page(struct sock *sk,
cork->length += size;
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)) {
skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -804,7 +804,7 @@ static int udp_send_skb(struct sk_buff *
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;
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1305,11 +1305,12 @@ emsgsize:
skb = skb_peek_tail(&sk->sk_write_queue);
cork->length += length;
- if ((((length + fragheaderlen) > mtu) ||
- (skb && skb_is_gso(skb))) &&
+ if ((skb && skb_is_gso(skb)) ||
+ (((length + fragheaderlen) > mtu) &&
+ (skb_queue_len(&sk->sk_write_queue) <= 1) &&
(sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO) &&
- (sk->sk_type == SOCK_DGRAM)) {
+ (sk->sk_type == SOCK_DGRAM))) {
err = ip6_ufo_append_data(sk, getfrag, from, length,
hh_len, fragheaderlen,
transhdrlen, mtu, flags, rt);
next prev parent reply other threads:[~2017-08-11 22:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-11 22:02 [PATCH 3.18 0/9] 3.18.65-stable review Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 1/9] tcp: avoid setting cwnd to invalid ssthresh after cwnd reduction states Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 2/9] net: fix keepalive code vs TCP_FASTOPEN_CONNECT Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 3/9] net: sched: set xt_tgchk_param par.nft_compat as 0 in ipt_init_target Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 4/9] tcp: fastopen: tcp_connect() must refresh the route Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 5/9] net: avoid skb_warn_bad_offload false positives on UFO Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 6/9] packet: fix tp_reserve race in packet_set_ring Greg Kroah-Hartman
2017-08-11 22:02 ` [PATCH 3.18 7/9] revert "ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output" Greg Kroah-Hartman
2017-08-11 22:02 ` Greg Kroah-Hartman [this message]
2017-08-11 22:02 ` [PATCH 3.18 9/9] ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output Greg Kroah-Hartman
2017-08-12 1:54 ` [PATCH 3.18 0/9] 3.18.65-stable review Shuah Khan
2017-08-12 12:22 ` Guenter Roeck
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