Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <c84c740a-582e-ff9e-2827-bf8eef5e6b0d@kernel.org>
Date:   Mon, 26 Jun 2023 18:38:18 +0900
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.12.0
Subject: Re: [PATCH] block: add check that partition length needs to be
 aligned with block size
Content-Language: en-US
To:     Min Li <min15.li@samsung.com>, axboe@kernel.dk,
        willy@infradead.org, hch@lst.de, gregkh@linuxfoundation.org
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
References: <CGME20230626091207epcas5p2a2957dfe97c4d82e39defa557d7ffd0e@epcas5p2.samsung.com>
 <20230626171021.5895-1-min15.li@samsung.com>
From:   Damien Le Moal <dlemoal@kernel.org>
Organization: Western Digital Research
In-Reply-To: <20230626171021.5895-1-min15.li@samsung.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 6/27/23 02:10, Min Li wrote:
> Before calling add partition or resize partition, there is no check
> on whether the length is aligned with the logical block size.
> If the logical block size of the disk is larger than 512 bytes,
> then the partition size maybe not the multiple of the logical block size,
> and when the last sector is read, bio_truncate() will adjust the bio size,
> resulting in an IO error if the size of the read command is smaller than
> the logical block size.If integrity data is supported, this will also
> result in a null pointer dereference when calling bio_integrity_free.
> 
> Signed-off-by: Min Li <min15.li@samsung.com>
> ---
>  block/ioctl.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/block/ioctl.c b/block/ioctl.c
> index 9c5f637ff153..aa95b5561169 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -35,6 +35,9 @@ static int blkpg_do_ioctl(struct block_device *bdev,
>  
>  	start = p.start >> SECTOR_SHIFT;
>  	length = p.length >> SECTOR_SHIFT;
> +	/*check if length is aligned to blocksize*/

Please add a space after /* and before */.

> +	if (p.length & (bdev_logical_block_size(bdev) - 1))
> +		return -EINVAL;

I would move this check before the "start = ...;" And while at it, I would also
move the check for p.start being aligned out of the "case BLKPG_ADD_PARTITION:"
together with this length alignment check. The p.start check is not needed for
BLKPG_RESIZE_PARTITION, but it will not hurt either.

>  
>  	switch (op) {
>  	case BLKPG_ADD_PARTITION:

-- 
Damien Le Moal
Western Digital Research