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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03AFFC433EF for ; Wed, 10 Nov 2021 14:58:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D171561051 for ; Wed, 10 Nov 2021 14:58:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232348AbhKJPBN (ORCPT ); Wed, 10 Nov 2021 10:01:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:44784 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232361AbhKJPBM (ORCPT ); Wed, 10 Nov 2021 10:01:12 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 271E56121F; Wed, 10 Nov 2021 14:58:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636556304; bh=bEYLEpQQ/QKPQQ1OXoATAhxucj4jMroHnPUyPDZXhY4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f1jSpjjjVxqXU2XTM9p8NxigTx/aKWoco2eyDBvti78m/lv/NvYKT5qm2sOVmhkr0 x4K3tfxY7zTXaiItbmovJmSqr8VRgXzCV2fdq3IZVFfLA/pyBTl+GUSQBw1E6OeTko f8AFQVYDFuHBIanKTMKsSEGhcg6cCwf/IOX/OXkMwwqglHOOQ9V+KN6OcgWOz/9g/z +Y72/tlDfLwsz0ABVaHzLnbBARcqjqxmB2vx9SzsrpkVQNDlUcfHqF6+Oy6Z2jG8no PmNudwvFiZHJkbVg6/nlUIX2/urAg8quvydxZgyJ6ngnn9u6uzXmgfi/hSqdumq/RP z9jlYip3Yadbg== From: SeongJae Park To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, SeongJae Park Subject: [PATCH 2/2] mm/damon/dbgfs: Fix missed use of damon_dbgfs_lock Date: Wed, 10 Nov 2021 14:57:58 +0000 Message-Id: <20211110145758.16558-3-sj@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211110145758.16558-1-sj@kernel.org> References: <20211110145758.16558-1-sj@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 commit fixes it by protecting all such accesses. Fixes: 75c1c2b53c78 ("mm/damon/dbgfs: support multiple contexts") Signed-off-by: SeongJae Park --- mm/damon/dbgfs.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index 8ce1311ac533..9b520bb4a3e7 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -877,12 +877,14 @@ static ssize_t dbgfs_monitor_on_write(struct file *file, return -EINVAL; } + mutex_lock(&damon_dbgfs_lock); if (!strncmp(kbuf, "on", count)) { int i; for (i = 0; i < dbgfs_nr_ctxs; i++) { if (damon_targets_empty(dbgfs_ctxs[i])) { kfree(kbuf); + mutex_unlock(&damon_dbgfs_lock); return -EINVAL; } } @@ -892,6 +894,7 @@ static ssize_t dbgfs_monitor_on_write(struct file *file, } else { ret = -EINVAL; } + mutex_unlock(&damon_dbgfs_lock); if (!ret) ret = count; @@ -944,15 +947,16 @@ 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; @@ -963,6 +967,8 @@ 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