From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: KVM induced panic on 2.6.38[2367] & 2.6.39 Date: Wed, 08 Jun 2011 00:57:07 +0200 Message-ID: <4DEEACC3.3030509@trash.net> References: <20110601011527.GN19505@random.random> <4DE5DCA8.7070704@fnarfbargle.com> <4DE5E29E.7080009@redhat.com> <4DE60669.9050606@fnarfbargle.com> <4DE60918.3010008@redhat.com> <4DE60940.1070107@redhat.com> <4DE61A2B.7000008@fnarfbargle.com> <20110601111841.GB3956@zip.com.au> <4DE62801.9080804@fnarfbargle.com> <20110601230342.GC3956@zip.com.au> <4DE8E3ED.7080004@fnarfbargle.com> <4DE906C0.6060901@fnarfbargle.com> <4DED344D.7000005@pandora.be> <4DED9C23.2030408@fnarfbargle.com> <4DEE27DE.7060004@trash.net> <4DEE3859.6070808@fnarfbargle.com> <4DEE4538.1020404@trash.net> <1307471484.3091.43.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Cc: Brad Campbell , Bart De Schuymer , kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org To: Eric Dumazet Return-path: In-Reply-To: <1307471484.3091.43.camel@edumazet-laptop> Sender: owner-linux-mm@kvack.org List-Id: netfilter-devel.vger.kernel.org On 07.06.2011 20:31, Eric Dumazet wrote: > Le mardi 07 juin 2011 =E0 17:35 +0200, Patrick McHardy a =E9crit : >=20 >> The main suspects would be NAT and TCPMSS. Did you also try whether >> the crash occurs with only one of these these rules? >> >>> I've just compiled out CONFIG_BRIDGE_NETFILTER and can no longer acce= ss >>> the address the way I was doing it, so that's a no-go for me. >> >> That's really weird since you're apparently not using any bridge >> netfilter features. It shouldn't have any effect besides changing >> at which point ip_tables is invoked. How are your network devices >> configured (specifically any bridges)? >=20 > Something in the kernel does=20 >=20 > u16 *ptr =3D addr (given by kmalloc()) >=20 > ptr[-1] =3D 0; >=20 > Could be an off-one error in a memmove()/memcopy() or loop... >=20 > I cant see a network issue here. So far me neither, but netfilter appears to trigger the bug. > I checked arch/x86/lib/memmove_64.S and it seems fine. I was thinking it might be a missing skb_make_writable() combined with vhost_net specifics in the netfilter code (TCPMSS and NAT are both suspect), but was unable to find something. I also went through the dst_metrics() conversion to see whether anything could cause problems with the bridge fake_rttable, but also nothing so far. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter= .ca/ Don't email: email@kvack.org