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From:   SeongJae Park <sj@kernel.org>
To:     SeongJae Park <sj@kernel.org>
Cc:     akpm@linux-foundation.org, ppbuk5246@gmail.com,
        damon@lists.linux.dev, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v4] damon/sysfs: Fix possible memleak on damon_sysfs_add_target.
Date:   Mon, 26 Sep 2022 16:23:26 +0000
Message-Id: <20220926162326.49013-1-sj@kernel.org>
In-Reply-To: <20220926160611.48536-1-sj@kernel.org>
References: 
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I forgot removing the closing dot of the subject and making the subject
lower-case.

On Mon, 26 Sep 2022 16:06:11 +0000 SeongJae Park <sj@kernel.org> wrote:

> From: Levi Yun <ppbuk5246@gmail.com>
> 
> 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.
> 
> By calling daemon_add_target as soon as allocating new target, Fix this

Also we should s/daemon/damon/

I will revise and send v5.

> possible memory leak.
> 
> Fixes: a61ea561c871 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring")
> Cc: <stable@vger.kernel.org> # 5.17.x
> Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
> Reviewed-by: SeongJae Park <sj@kernel.org>
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
> 
> Changes from v3
> (https://lore.kernel.org/damon/20220925234327.26345-1-ppbuk5246@gmail.com/)
> - Fix Fixes: tag
> - Add patch changelog
> 
> Changes from v2
> (https://lore.kernel.org/damon/20220925234053.26090-1-ppbuk5246@gmail.com/)
> - Add Fixes: and Cc: stable
> 
> Changes from v1
> (https://lore.kernel.org/damon/20220925140257.23431-1-ppbuk5246@gmail.com/)
> - Do damon_add_target() earlier instead of explicitly freeing the object
> 
>  mm/damon/sysfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 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;
> -- 
> 2.25.1