From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:53046 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934254AbeD0OHL (ORCPT ); Fri, 27 Apr 2018 10:07:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Subash Abhinov Kasiviswanathan , Sami Farin , Eric Dumazet , Soheil Hassas Yeganeh , Yuchung Cheng , Neal Cardwell Subject: [PATCH 4.14 33/80] tcp: clear tp->packets_out when purging write queue Date: Fri, 27 Apr 2018 15:58:26 +0200 Message-Id: <20180427135734.655295347@linuxfoundation.org> In-Reply-To: <20180427135732.928644313@linuxfoundation.org> References: <20180427135732.928644313@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Soheil Hassas Yeganeh Clear tp->packets_out when purging the write queue, otherwise tcp_rearm_rto() mistakenly assumes TCP write queue is not empty. This results in NULL pointer dereference. Also, remove the redundant `tp->packets_out = 0` from tcp_disconnect(), since tcp_disconnect() calls tcp_write_queue_purge(). Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST) Reported-by: Subash Abhinov Kasiviswanathan Reported-by: Sami Farin Tested-by: Sami Farin Signed-off-by: Eric Dumazet Signed-off-by: Soheil Hassas Yeganeh Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: Greg Kroah-Hartman --- include/net/tcp.h | 1 + net/ipv4/tcp.c | 1 - 2 files changed, 1 insertion(+), 1 deletion(-) --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1616,6 +1616,7 @@ static inline void tcp_write_queue_purge sk_mem_reclaim(sk); tcp_clear_all_retrans_hints(tcp_sk(sk)); tcp_init_send_head(sk); + tcp_sk(sk)->packets_out = 0; } static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2354,7 +2354,6 @@ int tcp_disconnect(struct sock *sk, int icsk->icsk_backoff = 0; tp->snd_cwnd = 2; icsk->icsk_probes_out = 0; - tp->packets_out = 0; tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; tp->snd_cwnd_cnt = 0; tp->window_clamp = 0;