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Date:   Thu, 18 Aug 2022 08:59:27 +0200 (CEST)
From:   Richard Weinberger <richard@nod.at>
To:     cuigaosheng <cuigaosheng1@huawei.com>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-mtd <linux-mtd@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        gongruiqi1@huawei.com, wangweiyang2@huawei.com
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In-Reply-To: <6733eee6-bfb6-7ee9-1331-2a739520fcd5@huawei.com>
References: <20220715071105.2321311-1-cuigaosheng1@huawei.com> <6733eee6-bfb6-7ee9-1331-2a739520fcd5@huawei.com>
Subject: Re: [PATCH -next] mtd/ftl: Fix memleak in ftl_add_mtd()
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Thread-Topic: mtd/ftl: Fix memleak in ftl_add_mtd()
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----- Ursprüngliche Mail -----
> Von: "cuigaosheng" <cuigaosheng1@huawei.com>
>
> PING

There seems to be a problem with your caps lock key. ;-)
 
> 在 2022/7/15 15:11, Gaosheng Cui 写道:
>> When add_mtd_blktrans_dev failed, partition's memory will be freed
>> by kfree, but there are some structure members that are allocated
>> for memory independently, such as partition->VirtualBlockMap,
>> partition->EUNInfo, partition->ZferInfo, and partition->bam_cache,
>> so kfree(partition) may cause memory leaks, using ftl_freepart(partition)
>> will fix it.

Is this leak observable via kmemleak or such?
I always thought ->remove_dev() unconditionally do a cleanup later.

>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>> Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
>> ---
>>   drivers/mtd/ftl.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
>> index f655d2905270..200271bdc7aa 100644
>> --- a/drivers/mtd/ftl.c
>> +++ b/drivers/mtd/ftl.c
>> @@ -1031,6 +1031,7 @@ static void ftl_add_mtd(struct mtd_blktrans_ops *tr,
>> struct mtd_info *mtd)
>>   		partition->mbd.devnum = -1;
>>   		if (!add_mtd_blktrans_dev(&partition->mbd))
>>   			return;
>> +		ftl_freepart(partition);
>>   	}
>>   
> >   	kfree(partition);