Commit eb5241a2 authored by Salvatore Bonaccorso's avatar Salvatore Bonaccorso

tcp: refine memory limit test in tcp_fragment()

Closes: #930904
parent 8fb3f0b2
linux (4.19.37-6) UNRELEASED; urgency=medium
* tcp: refine memory limit test in tcp_fragment() (Closes: #930904)
-- Salvatore Bonaccorso <carnil@debian.org> Sun, 23 Jun 2019 16:15:17 +0200
linux (4.19.37-5) unstable; urgency=medium
[ Romain Perier ]
......
From: Eric Dumazet <edumazet@google.com>
Date: Fri, 21 Jun 2019 06:09:55 -0700
Subject: tcp: refine memory limit test in tcp_fragment()
Origin: https://git.kernel.org/linus/b6653b3629e5b88202be3c9abc44713973f5c4b4
Bug-Debian: https://bugs.debian.org/930904
tcp_fragment() might be called for skbs in the write queue.
Memory limits might have been exceeded because tcp_sendmsg() only
checks limits at full skb (64KB) boundaries.
Therefore, we need to make sure tcp_fragment() wont punish applications
that might have setup very low SO_SNDBUF values.
Fixes: f070ef2ac667 ("tcp: tcp_fragment() should apply sane memory limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Christoph Paasch <cpaasch@apple.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp_output.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 00c01a01b547..0ebc33d1c9e5 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1296,7 +1296,8 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
if (nsize < 0)
nsize = 0;
- if (unlikely((sk->sk_wmem_queued >> 1) > sk->sk_sndbuf)) {
+ if (unlikely((sk->sk_wmem_queued >> 1) > sk->sk_sndbuf &&
+ tcp_queue != TCP_FRAG_IN_WRITE_QUEUE)) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPWQUEUETOOBIG);
return -ENOMEM;
}
--
2.20.1
......@@ -227,6 +227,7 @@ bugfix/all/tcp-limit-payload-size-of-sacked-skbs.patch
bugfix/all/tcp-tcp_fragment-should-apply-sane-memory-limits.patch
bugfix/all/tcp-add-tcp_min_snd_mss-sysctl.patch
bugfix/all/tcp-enforce-tcp_min_snd_mss-in-tcp_mtu_probing.patch
bugfix/all/tcp-refine-memory-limit-test-in-tcp_fragment.patch
# Fix exported symbol versions
bugfix/all/module-disable-matching-missing-version-crc.patch
......
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