Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752712Ab2KGRFJ (ORCPT ); Wed, 7 Nov 2012 12:05:09 -0500 Received: from mail-pb0-f46.google.com ([209.85.160.46]:62738 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751549Ab2KGRFH (ORCPT ); Wed, 7 Nov 2012 12:05:07 -0500 Subject: Re: [PATCH] tcp: Replace infinite loop on recvmsg bug with proper crashusers From: Eric Dumazet To: Dave Jones Cc: Julius Werner , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Patrick McHardy , Hideaki YOSHIFUJI , James Morris , Alexey Kuznetsov , "David S. Miller" , Sameer Nanda , Mandeep Singh Baines , Eric Dumazet In-Reply-To: <20121107164358.GA20495@redhat.com> References: <1352247335-10396-1-git-send-email-jwerner@chromium.org> <20121107013907.GA31185@redhat.com> <20121107155434.GA17677@redhat.com> <1352305752.3140.4449.camel@edumazet-glaptop> <20121107164358.GA20495@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 07 Nov 2012 09:05:02 -0800 Message-ID: <1352307902.3140.4588.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1720 Lines: 47 On Wed, 2012-11-07 at 11:43 -0500, Dave Jones wrote: > dude, look at the bug reports I just pointed you at. > People _are_ aware there are bugs there. > If I remember well, I helped to fix some of them. > If you turn that into a BUG() those reports would never have been filed. > How is that increasing awareness ? People are going to see wedged computers, > and hit the reset button. If we're lucky, we'll get photos of someone lucky > enough to have hit it while at the console, not in X. But this is a huge > step backwards for debugability. > > > I understand a distro maintainer has its own choices, but for upstream > > kernel we want to have early reports. > > I'm running out of ways to word this, but I'll try again. > You won't get those early reports if you turn this into a BUG(). > > > This bug is fatal and a security issue. BUG() is appropriate. > > turning a bug into a remote DoS is also a security issue. > Apparently in some cases we can loop and fill the syslog, or else Julius wouldnt have sent a patch. So the proper fix is to emit this message only once, and to find a way to alert the user security is compromised. So if BUG() isnt good, just use WARN_ON_ONCE() I feel that WARN_ON_ONCE() wont be clear enough to the user, especially if we recover from this by closing the tcp session, exactly as if we received a proper FIN. Really if you object a BUG() here, I cant understand you didnt shout to other BUG() uses in the kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/