tcp: refine memory limit test in tcp_fragment()

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: f070ef2ac6 ("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>
This commit is contained in:
Eric Dumazet 2019-06-21 06:09:55 -07:00 committed by David S. Miller
parent 85f9aa7565
commit b6653b3629

View File

@ -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;
}