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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Yuchung Cheng <ycheng@google.com>,
        Eric Dumazet <edumazet@google.com>,
        Neal Cardwell <ncardwell@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 043/162] tcp: fix off-by-one bug on aborting window-probing socket
Date:   Thu, 19 Dec 2019 19:32:31 +0100
Message-Id: <20191219183210.543197518@linuxfoundation.org>
In-Reply-To: <20191219183150.477687052@linuxfoundation.org>
References: <20191219183150.477687052@linuxfoundation.org>
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From: Yuchung Cheng <ycheng@google.com>

[ Upstream commit 3976535af0cb9fe34a55f2ffb8d7e6b39a2f8188 ]

Previously there is an off-by-one bug on determining when to abort
a stalled window-probing socket. This patch fixes that so it is
consistent with tcp_write_timeout().

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ipv4/tcp_timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 61359944acc71..710cde1a5a832 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -336,7 +336,7 @@ static void tcp_probe_timer(struct sock *sk)
 			return;
 	}
 
-	if (icsk->icsk_probes_out > max_probes) {
+	if (icsk->icsk_probes_out >= max_probes) {
 abort:		tcp_write_err(sk);
 	} else {
 		/* Only send another probe if we didn't close things up. */
-- 
2.20.1