From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44B073D80 for ; Sun, 25 Sep 2022 17:40:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 758AAC433D6; Sun, 25 Sep 2022 17:40:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664127615; bh=J6MQ6nba3bNXWm13BqriajL0itO1C/a8zLexNF1ZFAg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OkZq0jGhSkSPq3kPxaEBOl3PECjK2uwJU8qNaC8mEG878Nx9bpO9VH5hWpcNPtZSM 8NkHoT0XQOvB4qzY8nquutwdwOjgFIRjYGnhQmnThHYNzyn7xnyZlpBz9Be3dlB8jJ aCVo56CPytTSyD0RHmHgIqlMJGLJNU1UztPfbPryWs2LTKPjdrWK6Shf60MQQ0FOm0 paZ/GxPMeJ/Wt88zj70ZPOy5lDnNGtQBgILNuD8+YoBwTTDXWaGF+KnGeHSr7w5Cgx zZenW1YI/ihUwvNBJnzJrxDCKmGiZT9X4gE/Ddyea4ESq27QxhCHD+HiYdvMGA6aoC Uj7oCUZWPniMQ== From: SeongJae Park To: Levi Yun Cc: sj@kernel.org, akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org Subject: Re: [PATCH] damon/sysfs: Fix possible memleak on damon_sysfs_add_target. Date: Sun, 25 Sep 2022 17:40:13 +0000 Message-Id: <20220925174013.59565-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220925140257.23431-1-ppbuk5246@gmail.com> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Sun, 25 Sep 2022 23:02:57 +0900 Levi Yun wrote: > When damon_sysfs_add_target couldn't find proper task, > New allocated damon_target structure isn't registered yet, > So, it's impossible to free new allocated one by > damon_sysfs_destroy_targets. Good finding, thanks! > > By calling additional damon_free_target when find_get_pid function, > Fix possible memory leak. > > Signed-off-by: Levi Yun Could we add relevant 'Fixes: ' and 'Cc: ' tags? > --- > mm/damon/sysfs.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c > index 7488e27c87c3..28ed07d26d55 100644 > --- a/mm/damon/sysfs.c > +++ b/mm/damon/sysfs.c > @@ -2184,8 +2184,11 @@ static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target, > return -ENOMEM; > if (damon_target_has_pid(ctx)) { > t->pid = find_get_pid(sys_target->pid); > - if (!t->pid) > + if (!t->pid) { > + damon_free_target(t); > + Seems unnecessary new line? > goto destroy_targets_out; > + } > } Looks good to me, but... How about simply doing 'damon_add_target()' before 'if (damon_target_has_pid())', like below? ``` diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 455215a5c059..9f1219a67e3f 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -2172,12 +2172,12 @@ static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target, if (!t) return -ENOMEM; + damon_add_target(ctx, t); if (damon_target_has_pid(ctx)) { t->pid = find_get_pid(sys_target->pid); if (!t->pid) goto destroy_targets_out; } - damon_add_target(ctx, t); err = damon_sysfs_set_regions(t, sys_target->regions); if (err) goto destroy_targets_out; ``` Thanks, SJ > damon_add_target(ctx, t); > err = damon_sysfs_set_regions(t, sys_target->regions); > -- > 2.35.1 > >