From: Lennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Date: Wed, 17 Mar 2010 02:16:29 +0000 (+0000)
Subject: tcp: Fix tcp_mark_head_lost() with packets == 0
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~10^2~18381^2~192
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=6830c25b7d08fbbd922959425193791bc42079f2;p=linux-4.9.git

tcp: Fix tcp_mark_head_lost() with packets == 0

A packet is marked as lost in case packets == 0, although nothing should be done.
This results in a too early retransmitted packet during recovery in some cases.
This small patch fixes this issue by returning immediately.

Signed-off-by: Lennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Signed-off-by: Arnd Hannemann <hannemann@nets.rwth-aachen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 788851ca8c5d..c096a4218b8f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2511,6 +2511,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
 	int err;
 	unsigned int mss;
 
+	if (packets == 0)
+		return;
+
 	WARN_ON(packets > tp->packets_out);
 	if (tp->lost_skb_hint) {
 		skb = tp->lost_skb_hint;