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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DA1DC19F2A for ; Thu, 11 Aug 2022 22:01:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 937AA6B0073; Thu, 11 Aug 2022 18:01:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8C09B8E0002; Thu, 11 Aug 2022 18:01:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 761AE8E0001; Thu, 11 Aug 2022 18:01:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 64AD36B0073 for ; Thu, 11 Aug 2022 18:01:11 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 441E7A1957 for ; Thu, 11 Aug 2022 22:01:11 +0000 (UTC) X-FDA: 79788683142.02.606E04A Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf24.hostedemail.com (Postfix) with ESMTP id ACA6B1801A3 for ; Thu, 11 Aug 2022 22:01:09 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2F7AFB822EF; Thu, 11 Aug 2022 22:01:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99B01C43141; Thu, 11 Aug 2022 22:01:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1660255266; bh=0jzWSKGIa0lja44Of6Wk9nanVIqaf3tH8/GBEI38e+E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Ae+7QQXtxh/ub4KqOuWm93rAtjNxAU7txOnERHKUdtNsiPUmUOYjW4p+zdfB0ApNx KGay20cgP4rJrCnX6sTZ8s7H2acq5F6DRyXp3ObFLa1Jt6aSVvkD7vCCeLMMCOfWOH 53xMFxXF6guXABfBz45LXMlvHiBXEoTbpHXu5ZJE= Date: Thu, 11 Aug 2022 15:01:05 -0700 From: Andrew Morton To: Peter Xu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, David Hildenbrand , Mike Rapoport , Mike Kravetz , Andrea Arcangeli , Nadav Amit , Axel Rasmussen Subject: Re: [PATCH] mm/uffd: Reset write protection when unregister with wp-mode Message-Id: <20220811150105.ce8636e7f101545d12d6cfac@linux-foundation.org> In-Reply-To: References: <20220811201340.39342-1-peterx@redhat.com> <20220811141144.6aa509e68c5c7cd8b6c131b6@linux-foundation.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660255269; a=rsa-sha256; cv=none; b=LvQgReA2CUHTNd0fKetbO7oYQrRKegOeReS3to+utOEfeNksi3wkvSgfHzAfE1Mddk+e0X XFY7IcOlSvfV6wgRZnoBoMEnani8Fadjt1eD0de3ZR0N5d7d/G4TlHIEvWMdq2tg9Q8YI9 kOjhfRcxKmqYOKxGQ2E/H/wAcaayUmU= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=Ae+7QQXt; dmarc=none; spf=pass (imf24.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660255269; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=s+BM7XiwPvDWJ5rPiBH8ae1B8cYq9aJQUsk8j4xmZpA=; b=HCvzoLHcq01PC2wmL5ABPWmy289QQEWyEfN3KbydiWl8klaGzolRzS7/xX28TIjNR//fYu aFObEwc+lRScUnL0X77DgcJycL3e28n+Z5qa8Sl+gYoog/ri0PzmPtlEonZeT76/jA/wR5 yaxTnAB4qVdxCkPugv0IS6fZUfdfX28= X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: ACA6B1801A3 Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=Ae+7QQXt; dmarc=none; spf=pass (imf24.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspam-User: X-Stat-Signature: mxohk6kxs98795hmf869fd7my5sbghng X-HE-Tag: 1660255269-401198 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 Thu, 11 Aug 2022 17:23:14 -0400 Peter Xu wrote: > On Thu, Aug 11, 2022 at 02:11:44PM -0700, Andrew Morton wrote: > > On Thu, 11 Aug 2022 16:13:40 -0400 Peter Xu wrote: > > > > > I added a Fixes upon introducing of uffd-wp shmem+hugetlbfs because that's > > > the only issue reported so far and that's the commit David's reproducer > > > will start working (v5.19+). But the whole idea actually applies to not > > > only file memories but also anonymous. It's just that we don't need to fix > > > anonymous prior to v5.19- because there's no known way to exploit. > > > > I added a cc:stable to this. > > Thanks, Andrew. I'll remember to do so in future patches when Fixes apply. > Only if we want the fix to be backported! I mean, it's legitimate and sensible to add a Fixes: to a patch which fixes a comment typo, but we don't want that backported. And sometimes a fix is too complex and the problem too small to warrant a backport, but we still want that Fixes: tag.