From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99D36C2BA83 for ; Mon, 10 Feb 2020 00:52:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1F7C520714 for ; Mon, 10 Feb 2020 00:52:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="QZFaNkEZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F7C520714 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A92FE6B0082; Sun, 9 Feb 2020 19:52:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A43A96B0083; Sun, 9 Feb 2020 19:52:06 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95A3E6B0085; Sun, 9 Feb 2020 19:52:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0217.hostedemail.com [216.40.44.217]) by kanga.kvack.org (Postfix) with ESMTP id 7D11D6B0082 for ; Sun, 9 Feb 2020 19:52:06 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3FC9934A4 for ; Mon, 10 Feb 2020 00:52:06 +0000 (UTC) X-FDA: 76472390652.27.jelly96_86be3bbac440a X-HE-Tag: jelly96_86be3bbac440a X-Filterd-Recvd-Size: 2062 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Mon, 10 Feb 2020 00:52:05 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C7AAB20714; Mon, 10 Feb 2020 00:52:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581295924; bh=HLHy9ml8FiYb4A3BvNvDouXcuL9OmRbRdTekYypPsmg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=QZFaNkEZHNjzvsETtkzOfQ9coU5a1eYRM4U6tv7x49Oq1S8L93rkQw5i8+f9GnZK1 6lYj2puAiYQi7gy9XT2mwM98dQUW/2E4gmjQE7jotBaqTebWmGAsshVF0Nl/yqS/Ht TjyrxX7mpsqCGxZm7MmTc2Y36zPJoGqTeTmDg5hM= Date: Sun, 9 Feb 2020 16:52:04 -0800 From: Andrew Morton To: Li Xinhai Cc: linux-mm@kvack.org Subject: Re: [PATCH 0/3] mm: Fix misuse of parent anon_vma in dup_mmap path Message-Id: <20200209165204.73197330d083095e0ad18d6c@linux-foundation.org> In-Reply-To: <1581150928-3214-1-git-send-email-lixinhai.lxh@gmail.com> References: <1581150928-3214-1-git-send-email-lixinhai.lxh@gmail.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, 8 Feb 2020 08:35:25 +0000 Li Xinhai wrote: > This patchset fix the misuse of parenet anon_vma, which mainly caused by > child vma's vm_next and vm_prev are left same as its parent after > duplicate vma. Finally, code reached parent vma's neighbor by referring > pointer of child vma and executed wrong logic. > > The first two patches fix relevant issues, and the third patch sets vm_next > and vm_prev to NULL when duplicate vma to prevent potential misuse in future. What are the runtime effects of this bug? How is the bug triggered?