From: Soheil Hassas Yeganeh <soheil@google.com>
Date: Tue, 16 May 2017 21:39:02 +0000 (-0400)
Subject: tcp: warn on negative reordering values
X-Git-Tag: v4.13-rc1~157^2~411
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6f5b24eed0278136c29c27f2a7b3a2b6a202ac68;p=karo-tx-linux.git

tcp: warn on negative reordering values

Commit bafbb9c73241 ("tcp: eliminate negative reordering
in tcp_clean_rtx_queue") fixes an issue for negative
reordering metrics.

To be resilient to such errors, warn and return
when a negative metric is passed to tcp_update_reordering().

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bbadd79815a4..2fa55f57ac06 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -887,6 +887,9 @@ static void tcp_update_reordering(struct sock *sk, const int metric,
 	struct tcp_sock *tp = tcp_sk(sk);
 	int mib_idx;
 
+	if (WARN_ON_ONCE(metric < 0))
+		return;
+
 	if (metric > tp->reordering) {
 		tp->reordering = min(sysctl_tcp_max_reordering, metric);