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Date: Sat, 27 Jan 2024 12:44:09 +0300
From: Alexey Dobriyan <adobriyan@gmail.com>
To: Baokun Li <libaokun1@huawei.com>
Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca,
	jack@suse.cz, ritesh.list@gmail.com, linux-kernel@vger.kernel.org,
	yi.zhang@huawei.com, yangerkun@huawei.com, chengzhihao1@huawei.com,
	yukuai3@huawei.com, libaokun1@huawei.com
Subject: Re: [PATCH 1/7] ext4: avoid overflow when setting values via sysfs
Message-ID: <1da0649d-812f-4dee-9c1b-af567afa2e46@p183>
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Baokun Li wrote:

> @@ -463,6 +463,8 @@ static ssize_t ext4_attr_store(struct kobject *kobj,
>  		ret = kstrtoul(skip_spaces(buf), 0, &t);
>  		if (ret)
>  			return ret;
> +		if (t != (unsigned int)t)
> +			return -EINVAL;

kstrto*() interface has variants for all standard types.
It should be changed to kstrtou32() or kstrtouint();

If you check if kstrto*() result fits into another type,
you're probably doing it wrong.

>  		if (a->attr_ptr == ptr_ext4_super_block_offset)
>  			*((__le32 *) ptr) = cpu_to_le32(t);