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 4D2B9C433F5 for ; Mon, 27 Dec 2021 12:35:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 978636B0071; Mon, 27 Dec 2021 07:35:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 927D86B0072; Mon, 27 Dec 2021 07:35:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8171D6B0073; Mon, 27 Dec 2021 07:35:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0162.hostedemail.com [216.40.44.162]) by kanga.kvack.org (Postfix) with ESMTP id 6FEB46B0071 for ; Mon, 27 Dec 2021 07:35:45 -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 284098911B for ; Mon, 27 Dec 2021 12:35:45 +0000 (UTC) X-FDA: 78963520650.27.08E5E4B Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf01.hostedemail.com (Postfix) with ESMTP id 0DC9D40033 for ; Mon, 27 Dec 2021 12:35:34 +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 dfw.source.kernel.org (Postfix) with ESMTPS id C51ED60F3C; Mon, 27 Dec 2021 12:35:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4015C36AE7; Mon, 27 Dec 2021 12:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640608543; bh=5wQxYeJB7/dLdDA5xo4bBALbh/dwu0JreLF0QTgDcGM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nBAE1trlg07VNS4T4HxMrQ93w7rf7On4jqqqqMiiQfGAZ4w0BcPCZx7v8Hq99nvLj Cfw/cneUePnpHPpcJ9hlTsgKdHMs8bzXa07tjLzgQQVW5YYWnfWyewy+RNcPRz/pEF amS5vUOBpJDd3fNqN1nnuwn5bQvN3Jyg1IgJ8dkk= Date: Mon, 27 Dec 2021 13:35:40 +0100 From: Greg KH To: SeongJae Park Cc: stable@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [PATCH] mm/damon/dbgfs: protect targets destructions with kdamond_lock Message-ID: References: <20211226102632.836-1-sj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211226102632.836-1-sj@kernel.org> Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=nBAE1trl; dmarc=pass (policy=none) header.from=linuxfoundation.org; spf=pass (imf01.hostedemail.com: domain of gregkh@linuxfoundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 0DC9D40033 X-Stat-Signature: 7f7o4bz4npew9pf3sy3sz875gaqorpxd X-HE-Tag: 1640608534-239465 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 Sun, Dec 26, 2021 at 10:26:32AM +0000, SeongJae Park wrote: > commit 34796417964b8d0aef45a99cf6c2d20cebe33733 upstream. > > DAMON debugfs interface iterates current monitoring targets in > 'dbgfs_target_ids_read()' while holding the corresponding > 'kdamond_lock'. However, it also destructs the monitoring targets in > 'dbgfs_before_terminate()' without holding the lock. This can result in > a use_after_free bug. This commit avoids the race by protecting the > destruction with the corresponding 'kdamond_lock'. > > Link: https://lkml.kernel.org/r/20211221094447.2241-1-sj@kernel.org > Reported-by: Sangwoo Bae > Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") > Signed-off-by: SeongJae Park > Cc: # 5.15.x > Signed-off-by: Andrew Morton > Signed-off-by: Linus Torvalds > --- > This is a backport of a DAMON fix that merged in the mainline, for > v5.15.x stable series. Now queued up, thanks. greg k-h