From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753477AbZD2Jqz (ORCPT ); Wed, 29 Apr 2009 05:46:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752027AbZD2Jqq (ORCPT ); Wed, 29 Apr 2009 05:46:46 -0400 Received: from mx2.redhat.com ([66.187.237.31]:35487 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631AbZD2Jqp (ORCPT ); Wed, 29 Apr 2009 05:46:45 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20090429090654.GA8234@redhat.com> References: <20090429090654.GA8234@redhat.com> To: Oleg Nesterov Cc: dhowells@redhat.com, kpm@redhat.com, Roland McGrath , linux-kernel@vger.kernel.org Subject: Re: [PATCH] elf_core_dump: use rcu_read_lock() to access ->real_parent Date: Wed, 29 Apr 2009 10:46:43 +0100 Message-ID: <7146.1240998403@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Oleg Nesterov wrote: > (on top of ptrace-s-parent-real_parent-in-binfmt_elf_fdpicc.patch) > > In theory it is not safe to dereference ->parent/real_parent without > tasklist or rcu lock, we can race with re-parenting. > > Signed-off-by: Oleg Nesterov Acked-by: David Howells