From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gao feng Subject: Re: [PATCH] ipv6: release referenct of ip6_null_entry's dst entry in __ip6_del_rt Date: Mon, 24 Sep 2012 12:32:14 +0800 Message-ID: <505FE24E.4030204@cn.fujitsu.com> References: <1348118734-2967-1-git-send-email-gaofeng@cn.fujitsu.com> <20120921.131652.353726055575103840.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:48273 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751379Ab2IXEcL convert rfc822-to-8bit (ORCPT ); Mon, 24 Sep 2012 00:32:11 -0400 In-Reply-To: <20120921.131652.353726055575103840.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: =E4=BA=8E 2012=E5=B9=B409=E6=9C=8822=E6=97=A5 01:16, David Miller =E5=86= =99=E9=81=93: > From: Gao feng > Date: Thu, 20 Sep 2012 13:25:34 +0800 >=20 >> as we hold dst_entry before we call __ip6_del_rt, >> so we should alse call dst_release not only return >> -ENOENT when the rt6_info is ip6_null_entry. >> >> and we already hold the dst entry, so I think it's >> safe to call dst_release out of the write-read lock. >> >> Signed-off-by: Gao feng >=20 > I cannot find a code path where we can actually end up > with an ip6_null_entry here and I'd much rather declare > this condition as a bug. >=20 > Patrick McHardy added this check back in 2006: >=20 > commit 6c813a7297e3af4cd7c3458e09e9ee3d161c6830 > Author: Patrick McHardy > Date: Sun Aug 6 22:22:47 2006 -0700 >=20 > [IPV6]: Fix crash in ip6_del_rt >=20 > But the ipv6 code has changed substantially since then. ip -6 route del ::/0 will end up with an ip6_null_entry. so I think this checking and this patch is needed .