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 60FC0C19F2D for ; Wed, 10 Aug 2022 01:57:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ECE838E0002; Tue, 9 Aug 2022 21:57:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E7E8F8E0001; Tue, 9 Aug 2022 21:57:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D1E818E0002; Tue, 9 Aug 2022 21:57:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id BF4EB8E0001 for ; Tue, 9 Aug 2022 21:57:18 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id A05D1AB9BE for ; Wed, 10 Aug 2022 01:57:18 +0000 (UTC) X-FDA: 79782020556.09.EEA07DB Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf07.hostedemail.com (Postfix) with ESMTP id 2FE8A40167 for ; Wed, 10 Aug 2022 01:57:18 +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 B495EB81661; Wed, 10 Aug 2022 01:57:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08B24C433B5; Wed, 10 Aug 2022 01:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1660096635; bh=fzCgWcg8Y/G5tPN9s9vV3n0S/OCtwwmdTi510NoLYWY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sex+uwmZgfCLP06EebthP+QPfEoWpHyYrkh+tgeBjGLKhDr05wc+gDNTRs4k1KHjV X0RNvllP63xrrW5MSVkCjYse9f8zAZncBzGSYy+7v6e2ob6sBfZ4TFjtlmocF4dkq4 cWULzNfx7AHAa4jvvhBlBEaYgSS0zMtifWZRiqeo= Date: Tue, 9 Aug 2022 18:57:14 -0700 From: Andrew Morton To: Charan Teja Kalla Cc: , , , , , , , , , , Subject: Re: [PATCH V3] mm: fix use-after free of page_ext after race with memory-offline Message-Id: <20220809185714.5af7057c1270b11079cb196a@linux-foundation.org> In-Reply-To: <1660056403-20894-1-git-send-email-quic_charante@quicinc.com> References: <1660056403-20894-1-git-send-email-quic_charante@quicinc.com> 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-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660096638; 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=oeG4TzwCozt/MifAogRN/i8sPvi0dSawIbaVjlNzqmc=; b=8PTuUjdRTC39Z+ys3LScp0cdLfkcdeI7gL76PWdTYYlrhRWbm7JkeA8oFhI580Hfn28j9r h8hXAD2N3hzmBB//35RsxwFnS8kMfT0Dm/bD6VWdSkkcczO1J3svCZHJlrixXUa0543hK9 cennYjHfS1oD3aWxZuqL+gCVMEb9AUY= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=sex+uwmZ; dmarc=none; spf=pass (imf07.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660096638; a=rsa-sha256; cv=none; b=OutTSSfm2Vjhc5+Yq6E5B8RwsRMyRCzTwO3zUOYK9sbFfZPN95ybaoy/CVOEaaRFb2yVJK iH2S7WF1LsjSGHZBwbeZY6LFjcK817UeBXpTZKzUlVVVLzeNg6FKbYNOY2OS3wRSBZecMv SJPbrVzJGAjgWO4KY4y8/aPWnx1mCRo= X-Rspamd-Queue-Id: 2FE8A40167 X-Rspamd-Server: rspam03 X-Rspam-User: Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=sex+uwmZ; dmarc=none; spf=pass (imf07.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Stat-Signature: cj41twroz66hhn5xpy4jntxktk6fiei1 X-HE-Tag: 1660096638-654117 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 Tue, 9 Aug 2022 20:16:43 +0530 Charan Teja Kalla wrote: > The below is one path where race between page_ext and offline of the > respective memory blocks will cause use-after-free on the access of > page_ext structure. Has this race ever been observed at runtime? Given the size of the fix, I'm looking for excuses to not backport it into -stable kernels!