linux-kernel - Re: [PATCH] ubi: fastmap: fix ubi->fm memory leak

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Message-ID: <20251107021137.874150-1-pangliyuan1@huawei.com>
Date: Fri, 7 Nov 2025 10:11:37 +0800
From: Liyuan Pang <pangliyuan1@...wei.com>
To: <markus.elfring@....de>
CC: <alexandre.torgue@...s.st.com>, <chengzhihao1@...wei.com>,
	<linux-arm-kernel@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
	<linux-mtd@...ts.infradead.org>, <linux-stm32@...md-mailman.stormreply.com>,
	<mcoquelin.stm32@...il.com>, <miquel.raynal@...tlin.com>,
	<pangliyuan1@...wei.com>, <richard@....at>, <vigneshr@...com>,
	<wanqian10@...wei.com>, <young.liuyang@...wei.com>
Subject: Re: [PATCH] ubi: fastmap: fix ubi->fm memory leak

On Thu, 6 Nov 2025 16:16:05 +0100, Markus Elfring wrote:
>…
>> +++ b/drivers/mtd/ubi/fastmap.c
>> @@ -1644,3 +1644,15 @@ int ubi_update_fastmap(struct ubi_device *ubi)
>…
>> +void ubi_free_fastmap(struct ubi_device *ubi)
>> +{
>> +	int i;
>> +
>> +	if (ubi->fm) {
> +		for (i = 0; i < ubi->fm->used_blocks; i++)
> +			kmem_cache_free(ubi_wl_entry_slab, ubi->fm->e[i]);
>…
> +	}
> +}
>…
>
> May the local variable “i” be defined in the loop header?

I think it's better to leave it as it is, most of the code in
ubi defines variables outside the loop header, and defining
"i" in the loop header may cause compilation error in some old
kernel versions that use C89.

Regards,
Liyuan