From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58C4BC7618B for ; Fri, 26 Jul 2019 14:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EB632082E for ; Fri, 26 Jul 2019 14:54:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564152884; bh=gGl9USF6emdxxDmy62/p86tB76QQQkpMveALm288CQo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=GbfVrVKKVSE/wcx6IFTlNoVc2e/OjrS+Wlc3bVK/lNaQD7OUn1zzJXZnXwIUB1bWV 3T15re1d5gq+LBBbhSkRHoU4oY+YyKstZXIt2C2nI6deoYmY3z63FAaM4tel5ecMNN Rrp4jf+SRGtMRTY5FKh3oLomg95nlRbOdbXabHuw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727294AbfGZOyn (ORCPT ); Fri, 26 Jul 2019 10:54:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:57142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727172AbfGZOyn (ORCPT ); Fri, 26 Jul 2019 10:54:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A79B72070B; Fri, 26 Jul 2019 14:54:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564152882; bh=gGl9USF6emdxxDmy62/p86tB76QQQkpMveALm288CQo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P4aPWad454cEG2dHgRAQsWJLlr+KPFPu2AK3ePCcn26NzFybZnAcR+OYjjhMh+dy1 YjuKCtLFuFwvtQA2IeCrxf9piuacTQ9LsHg8LvWNj006fQqRF2s1sNc4Qe7n31IWZR qSVxlRrE+YT19B68HGF/QgQWrEX8+h/LuI4qEKjw= Date: Fri, 26 Jul 2019 16:54:39 +0200 From: Greg KH To: Eric Dumazet Cc: Andrew Prout , Christoph Paasch , David Miller , Jonathan Lemon , Jonathan Looney , Michal Kubecek , Neal Cardwell , Yuchung Cheng , stable@vger.kernel.org Subject: Re: FAILED: patch "[PATCH] tcp: be more careful in tcp_fragment()" failed to apply to 4.14-stable tree Message-ID: <20190726145439.GA10750@kroah.com> References: <1564144694159130@kroah.com> <20190726124517.GA8301@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Jul 26, 2019 at 04:39:48PM +0200, Eric Dumazet wrote: > On Fri, Jul 26, 2019 at 2:45 PM Greg KH wrote: > > > > On Fri, Jul 26, 2019 at 02:38:14PM +0200, gregkh@linuxfoundation.org wrote: > > > > > > The patch below does not apply to the 4.14-stable tree. > > > If someone wants it applied there, or to any other stable or longterm > > > tree, then please email the backport, including the original git commit > > > id to . > > > > > > thanks, > > > > > > greg k-h > > > > > > ------------------ original commit in Linus's tree ------------------ > > > > > > >From b617158dc096709d8600c53b6052144d12b89fab Mon Sep 17 00:00:00 2001 > > > From: Eric Dumazet > > > Date: Fri, 19 Jul 2019 11:52:33 -0700 > > > Subject: [PATCH] tcp: be more careful in tcp_fragment() > > > > > > Some applications set tiny SO_SNDBUF values and expect > > > TCP to just work. Recent patches to address CVE-2019-11478 > > > broke them in case of losses, since retransmits might > > > be prevented. > > > > > > We should allow these flows to make progress. > > > > > > This patch allows the first and last skb in retransmit queue > > > to be split even if memory limits are hit. > > > > > > It also adds the some room due to the fact that tcp_sendmsg() > > > and tcp_sendpage() might overshoot sk_wmem_queued by about one full > > > TSO skb (64KB size). Note this allowance was already present > > > in stable backports for kernels < 4.15 > > > > > > Note for < 4.15 backports : > > > tcp_rtx_queue_tail() will probably look like : > > > > > > static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) > > > { > > > struct sk_buff *skb = tcp_send_head(sk); > > > > > > return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk); > > > } > > > > > > Note, I tried the above, but still ran into problems a 4.14 does not > > have tcp_rtx_queue_head() and while I could guess as to what it would be > > (tcp_sent_head()?), I figured it would be safer to ask for a backport :) > > > > > tcp_rtx_queue_head(sk) would be implemented by : > { > struct sk_buff *skb = tcp_write_queue_head(sk); > if (skb == tcp_send_head(sk)) > skb = NULL; > return skb; > } > > I can provide the backport, of course. A backport would be great to ensure I didn't mess it up :) thanks, greg k-h