Message-ID: <e067a2a8-5445-52aa-c89b-490ad4350d19@huawei.com>
Date:   Tue, 4 Jan 2022 10:34:33 +0800
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Subject: Re: [PATCH] setup_tdb : fix memory leak
To:     riteshh <riteshh@linux.ibm.com>
CC:     Theodore Ts'o <tytso@mit.edu>, <linux-ext4@vger.kernel.org>,
        <liuzhiqiang26@huawei.com>, <linfeilong@huawei.com>
References: <3a0cbb4e-6ea3-356a-433d-3a7a6466b018@huawei.com>
 <20220103122202.tz6wv5tyf4xmeb2t@riteshh-domain>
From:   zhanchengbin <zhanchengbin1@huawei.com>
In-Reply-To: <20220103122202.tz6wv5tyf4xmeb2t@riteshh-domain>
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Yes, you are right. I will submit Patch V2 in the future.

在 2022/1/3 20:31, riteshh 写道:
> On 21/11/30 02:40PM, zhanchengbin wrote:
>> In setup_tdb(), need free tdb_dir before return,
>> otherwise it will cause memory leak.
>>
>> Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
>> Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
>> ---
>>   e2fsck/dirinfo.c | 13 +++++++++----
>>   1 file changed, 9 insertions(+), 4 deletions(-)
>>
>> diff --git a/e2fsck/dirinfo.c b/e2fsck/dirinfo.c
>> index 49d624c5..a2b36d8e 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 error;
>>
>>   	retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
> 
> I think freeing of db->tdb_fn should also be handled in case of an error.
> 
>>   	if (retval)
>> -		return;
>> +		goto 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 error;
> 
> So in case of an error we should call ext2fs_free_mem(&db->tdb_fn), right?
> 
> Rest looks good to me.
> 
> -ritesh
> 
> 
>>   	}
>>
>>   	if (num_dirs < 99991)
>> @@ -83,6 +83,11 @@ 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);
>> +
>> +error:
>> +	if(tdb_dir) {
>> +		free(tdb_dir);
>> +	}
>>   }
>>   #endif
>>
>> --
>> 2.23.0
>>
>>
> .
>