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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24842C433EF for ; Sun, 21 Nov 2021 11:02:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238053AbhKULFf (ORCPT ); Sun, 21 Nov 2021 06:05:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:34432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238054AbhKULFe (ORCPT ); Sun, 21 Nov 2021 06:05:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B67AD608FB; Sun, 21 Nov 2021 11:02:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637492549; bh=Ufdx8ARO4THgjUCgnF+gxz8aDr/YgOiNmfXPT9ZpqNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZBF83KaobljbaaJHUuggWujZFm3neyoLpPN16qo3IUNGlLYGLYtmBB/l6Mko3JQEY qfRHQbd0pnJpTKrTHsaEWFxkFnCeGL3disH4QTConTzOfDroNBhIbV5868l6TOYEux tdzZRbAk/PPtkBv7RFRY5kK+UgLKT24sRlUSSqkBCueWwn4IFl2oq7/3yEgQwkU69O g5blPr7aZhJ088ee+TAVwMjQzzaQNpzPPeHTpC4iYV0m+FbCGdMfKvV9kpcHJoQibq mll/nT7nliW+YpMVBsdbzEbRXV/p/p+wsPpXNjGo9XgQvMWno2lR1piAPa8HTcde2Z frViPCtFB7Ygw== From: SeongJae Park To: stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, SeongJae Park , Linus Torvalds Subject: [PATCH for-5.15.x 2/2] mm/damon/dbgfs: fix missed use of damon_dbgfs_lock Date: Sun, 21 Nov 2021 11:02:11 +0000 Message-Id: <20211121110211.17032-3-sj@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211121110211.17032-1-sj@kernel.org> References: <20211121110211.17032-1-sj@kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit d78f3853f831eee46c6dbe726debf3be9e9c0d05 upstream. DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and dbgfs_dirs using damon_dbgfs_lock. However, some of the code is accessing the variables without the protection. This fixes it by protecting all such accesses. Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org Fixes: 75c1c2b53c78 ("mm/damon/dbgfs: support multiple contexts") Signed-off-by: SeongJae Park Cc: # 5.15.x Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/damon/dbgfs.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index 2741ff79e8e8..f94d19a690df 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -538,12 +538,14 @@ static ssize_t dbgfs_monitor_on_write(struct file *file, return -EINVAL; } + mutex_lock(&damon_dbgfs_lock); if (!strncmp(kbuf, "on", count)) err = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs); else if (!strncmp(kbuf, "off", count)) err = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs); else err = -EINVAL; + mutex_unlock(&damon_dbgfs_lock); if (err) ret = err; @@ -596,15 +598,16 @@ static int __init __damon_dbgfs_init(void) static int __init damon_dbgfs_init(void) { - int rc; + int rc = -ENOMEM; + mutex_lock(&damon_dbgfs_lock); dbgfs_ctxs = kmalloc(sizeof(*dbgfs_ctxs), GFP_KERNEL); if (!dbgfs_ctxs) - return -ENOMEM; + goto out; dbgfs_ctxs[0] = dbgfs_new_ctx(); if (!dbgfs_ctxs[0]) { kfree(dbgfs_ctxs); - return -ENOMEM; + goto out; } dbgfs_nr_ctxs = 1; @@ -615,6 +618,8 @@ static int __init damon_dbgfs_init(void) pr_err("%s: dbgfs init failed\n", __func__); } +out: + mutex_unlock(&damon_dbgfs_lock); return rc; } -- 2.17.1