Date:   Tue, 4 Jan 2022 17:07:49 +0530
From:   riteshh <riteshh@linux.ibm.com>
To:     zhanchengbin <zhanchengbin1@huawei.com>
Cc:     "Theodore Ts'o" <tytso@mit.edu>, linux-ext4@vger.kernel.org,
        liuzhiqiang26@huawei.com, linfeilong@huawei.com
Subject: Re: [PATCH v2] setup_tdb : fix memory leak
Message-ID: <20220104113749.meyk7zkdtrqgwoc2@riteshh-domain>
References: <968b7f2c-6030-35c3-bc65-06a80b6e2403@huawei.com>
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In-Reply-To: <968b7f2c-6030-35c3-bc65-06a80b6e2403@huawei.com>
Precedence: bulk

On 22/01/04 07:21PM, zhanchengbin wrote:
> In setup_tdb(), need free tdb_dir and db->tdb_fn before return,
> otherwise it will cause memory leak.
>
> Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
> Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
> ---
>  e2fsck/dirinfo.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/e2fsck/dirinfo.c b/e2fsck/dirinfo.c
> index 49d624c5..97a303e5 100644
> --- a/e2fsck/dirinfo.c
> +++ b/e2fsck/dirinfo.c
> @@ -49,7 +49,7 @@ static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
>  	ext2_ino_t		threshold;
>  	errcode_t		retval;
>  	mode_t			save_umask;
> -	char			*tdb_dir, uuid[40];
> +	char			*tdb_dir = NULL, uuid[40];
>  	int			fd, enable;
>
>  	profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
> @@ -61,11 +61,11 @@ static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
>
>  	if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
>  	    (threshold && num_dirs <= threshold))
> -		return;
> +		goto tdb_dir_error;
>
>  	retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
>  	if (retval)
> -		return;
> +		goto tdb_dir_error;
>
>  	uuid_unparse(ctx->fs->super->s_uuid, uuid);
>  	sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
> @@ -74,7 +74,7 @@ static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
>  	umask(save_umask);
>  	if (fd < 0) {
>  		db->tdb = NULL;
> -		return;
> +		goto tdb_fn_error;
>  	}
>
>  	if (num_dirs < 99991)
> @@ -83,6 +83,16 @@ static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
>  	db->tdb = tdb_open(db->tdb_fn, num_dirs, TDB_NOLOCK | TDB_NOSYNC,
>  			   O_RDWR | O_CREAT | O_TRUNC, 0600);
>  	close(fd);
> +
> +	return;
> +
> +tdb_fn_error:
> +	ext2fs_free_mem(&db->tdb_fn);
> +	db->tdb_fn = NULL;

I think making tdb_fn = NULL is not needed, since ext2fs_free_mem() takes care of it.
With that removed, feel free to add:

Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>

-riteshh


> +tdb_dir_error:
> +	if (tdb_dir) {
> +		free(tdb_dir);
> +	}
>  }
>  #endif
>
> --
> 2.27.0
>