From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 5 May 2001 19:18:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 5 May 2001 19:18:01 -0400 Received: from thepigsty.demon.co.uk ([158.152.99.38]:56269 "EHLO mad.pigsty.org.uk") by vger.kernel.org with ESMTP id ; Sat, 5 May 2001 19:17:57 -0400 To: linux-kernel@vger.kernel.org, Andi Kleen Subject: ipv6 activity causing system hang in kernel 2.4.4 From: Tim Haynes Reply-To: kernel@stirfried.vegetable.org.uk (Tim Haynes) Date: 06 May 2001 00:17:47 +0100 Message-ID: <871yq3mllw.fsf@straw.pigsty.org.uk> User-Agent: Gnus/5.090003 (Oort Gnus v0.03) XEmacs/21.1 (Cuyahoga Valley) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org [I can't see evidence of this being reported before; apols if I'm wrong. Please also Cc: me as I only read l-k intermittently but would like to help out more.] Hi, I've been making very tentative forays into IPv6. However, in my simple experiments thus far I appear to have located a bug: 1/ configure 2 machines with site-local IP#s - I'm using ifconfig eth0 inet6 add fec0:1234:5:6::n 2/ flood-ping from one to the other 3/ after about 15s, watch one box hang, needing magic-sysreq or hard reset This is only with kernel 2.4.4; 2.4.2, 2.4.3 and NetBSD boxes are not affected. It is independent of platform; I've reproduced it at will on a lowly p75, an athlon, a p3-800 and on a powerbook/PPC. All kernels are compiled to have ipv6 modular, netfilter modular... everything with which I'm playing, modular. Compiler versions: | zsh, 12:06AM % gcc -v | Reading specs from /usr/lib/gcc-lib/powerpc-linux/2.95.4/specs | gcc version 2.95.4 20010319 (Debian prerelease) | zsh, 12:06AM % gcc -v | Reading specs from /usr/lib/gcc-lib/i386-linux/2.95.4/specs | gcc version 2.95.4 20010319 (Debian prerelease) (I'm tracking Debian/Unstable here.) I have tcpdump logs ( - they're 570K apiece); the `victim' machine receives nothing but ping-requests and sends nothing but ping-replies until the file is truncated; the surviving box sends nothing but requests and receives nothing but replies until it becomes requests-only. (IOW there is no evidence of ARP, fragmentation traffic, only the pings.) The Changelog lists an `IPv6 packet re-assembly fix' in -pre2; my suspicions lie in this area or with my compiler. If there's anything else I can provide by way of diagnostics, please let me know. Cheers, ~Tim --