Received-SPF: pass (google.com: domain of linux-kernel+bounces-110804-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Message-ID: <0049877f-a6c0-4dc5-977f-13aa193cd38b@kernel.org>
Date: Fri, 22 Mar 2024 08:53:04 +0900
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 5.10/5.15] scsi: add a length check for
 VARIABLE_LENGTH_CMD commands
To: Mikhail Ukhin <mish.uxin2012@yandex.ru>, Jens Axboe <axboe@kernel.dk>
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
 Niklas Cassel <cassel@kernel.org>, Pavel Koshutin
 <koshutin.pavel@yandex.ru>, Artem Sadovnikov <ancowi69@gmail.com>,
 Mikhail Ivanov <iwanov-23@bk.ru>
References: <20240321110229.9534-1-mish.uxin2012@yandex.ru>
Content-Language: en-US
From: Damien Le Moal <dlemoal@kernel.org>
Organization: Western Digital Research
In-Reply-To: <20240321110229.9534-1-mish.uxin2012@yandex.ru>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

On 3/21/24 20:02, Mikhail Ukhin wrote:
> Fuzzing of 5.10 stable branch reports a slab-out-of-bounds error in
> ata_scsi_pass_thru.
> 
> The error is fixed in 5.18 by commit
> ce70fd9a551af7424a7dace2a1ba05a7de8eae27.
> Backporting this commit would require significant changes to the code so
> it is bettter to use a simple fix for that particular error.
> 
> The problem is that the length of the received SCSI command is not
> validated if scsi_op == VARIABLE_LENGTH_CMD. It can lead to out-of-bounds
> reading if the user sends a request with SCSI command of length less than
> 32.
> 
> Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
> 
> Signed-off-by: Artem Sadovnikov <ancowi69@gmail.com>
> Signed-off-by: Mikhail Ivanov <iwanov-23@bk.ru>

Looks OK to me, but the patch title prefix is incorrect since this is not a scsi
patch. Please make that:

ata: libata-scsi: check cdb length for VARIABLE_LENGTH_CMD commands

> ---
>  drivers/ata/libata-scsi.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index dfa090ccd21c..77589e911d3d 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -4065,6 +4065,9 @@ int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
>  
>  	if (unlikely(!scmd->cmd_len))
>  		goto bad_cdb_len;
> +
> +	if (scsi_op == VARIABLE_LENGTH_CMD && scmd->cmd_len < 32)
> +		goto bad_cdb_len;
>  
>  	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
>  		if (unlikely(scmd->cmd_len > dev->cdb_len))

-- 
Damien Le Moal
Western Digital Research