From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33326 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932073AbeFXPt1 (ORCPT ); Sun, 24 Jun 2018 11:49:27 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Soheil Hassas Yeganeh , Wei Wang , Neal Cardwell , "David S. Miller" , Benjamin Gilbert , Guenter Roeck Subject: [PATCH 4.9 12/39] tcp: do not overshoot window_clamp in tcp_rcv_space_adjust() Date: Sun, 24 Jun 2018 23:23:59 +0800 Message-Id: <20180624152353.398772600@linuxfoundation.org> In-Reply-To: <20180624152352.038950449@linuxfoundation.org> References: <20180624152352.038950449@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 02db55718d53f9d426cee504c27fb768e9ed4ffe upstream. While rcvbuf is properly clamped by tcp_rmem[2], rcvwin is left to a potentially too big value. It has no serious effect, since : 1) tcp_grow_window() has very strict checks. 2) window_clamp can be mangled by user space to any value anyway. tcp_init_buffer_space() and companions use tcp_full_space(), we use tcp_win_from_space() to avoid reloading sk->sk_rcvbuf Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Acked-by: Wei Wang Acked-by: Neal Cardwell Signed-off-by: David S. Miller Cc: Benjamin Gilbert Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -636,7 +636,7 @@ void tcp_rcv_space_adjust(struct sock *s sk->sk_rcvbuf = rcvbuf; /* Make the window clamp follow along. */ - tp->window_clamp = rcvwin; + tp->window_clamp = tcp_win_from_space(rcvbuf); } } tp->rcvq_space.space = copied;