From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: oops / null deref in __inet6_check_established(), kernel 2.6.29-rc6 Date: Sun, 01 Mar 2009 21:33:28 -0800 (PST) Message-ID: <20090301.213328.103151098.davem@davemloft.net> References: <20090224.152704.210992553.davem@davemloft.net> <20090224183554.330eb308@dhcp-100-2-144.bos.redhat.com> <20090228031618.GB28503@bombadil.infradead.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: cebbert@redhat.com, netdev@vger.kernel.org To: kyle@infradead.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:36551 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750730AbZCBFdq (ORCPT ); Mon, 2 Mar 2009 00:33:46 -0500 In-Reply-To: <20090228031618.GB28503@bombadil.infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Kyle McMartin Date: Fri, 27 Feb 2009 22:16:18 -0500 > From: Kyle McMartin > > This only seems to show up when CONFIG_NET_NS is enabled. (Reproduced on > git HEAD with that option on, doesn't occur with the option off.) > > I will confess complete ignorance to the network stack, but this patch > fixes things... ipv4 seems to have the same namespace support, but > increments the sock_net, not the twsk_net. > > I'll probably put this patch into Fedora, if only to prevent this from > being used as a local DoS by an unprivileged user. > > Signed-off-by: Kyle McMartin Pavel already submitted a fix for this and it's in my net-2.6 tree and therefore will be sent to Linus soon. And thanks so much for your amazing patience. commit 3f53a38131a4e7a053c0aa060aba0411242fb6b9 Author: Pavel Emelyanov Date: Thu Feb 26 03:35:13 2009 -0800 ipv6: don't use tw net when accounting for recycled tw We already have a valid net in that place, but this is not just a cleanup - the tw pointer can be NULL there sometimes, thus causing an oops in NET_NS=y case. The same place in ipv4 code already works correctly using existing net, rather than tw's one. The bug exists since 2.6.27. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c index 8fe267f..1bcc343 100644 --- a/net/ipv6/inet6_hashtables.c +++ b/net/ipv6/inet6_hashtables.c @@ -258,11 +258,11 @@ unique: if (twp != NULL) { *twp = tw; - NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITRECYCLED); + NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED); } else if (tw != NULL) { /* Silly. Should hash-dance instead... */ inet_twsk_deschedule(tw, death_row); - NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITRECYCLED); + NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED); inet_twsk_put(tw); }