Subject: [PATCH 29/31] tcp: fastopen: avoid negative sk_forward_alloc

From: Eric Dumazet <[email-masked]>
Date: Wed, 7 Sep 2016 08:34:11 -0700

[ Upstream commit 76061f631c2ea4ab9c4d66f3a96ecc5737f5aaf7 ]

When DATA and/or FIN are carried in a SYN/ACK message or SYN message,
we append an skb in socket receive queue, but we forget to call
sk_forced_mem_schedule().

Effect is that the socket has a negative sk->sk_forward_alloc as long as
the message is not read by the application.

Josh Hunt fixed a similar issue in commit d22e15371811 ("tcp: fix tcp
fin memory accounting")

Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path")
Signed-off-by: Eric Dumazet <[email-masked]>
Reviewed-by: Josh Hunt <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/ipv4/tcp_fastopen.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 54d9f9b..478114b 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -150,6 +150,7 @@ void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb)
 	tp->segs_in = 0;
 	tcp_segs_in(tp, skb);
 	__skb_pull(skb, tcp_hdrlen(skb));
+	sk_forced_mem_schedule(sk, skb->truesize);
 	skb_set_owner_r(skb, sk);
 
 	TCP_SKB_CB(skb)->seq++;
-- 
2.1.0