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Date:   Mon, 28 Nov 2022 12:06:45 +0300
From:   "Kirill A. Shutemov" <kirill@shutemov.name>
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc:     jejb@linux.ibm.com, martin.petersen@oracle.com,
        linux-scsi@vger.kernel.org, dave.hansen@linux.intel.com,
        David.Laight@ACULAB.COM, linux-kernel@vger.kernel.org,
        x86@kernel.org
Subject: Re: [PATCHv2] scsi: Fix get_user() in call sg_scsi_ioctl()
Message-ID: <20221128090645.i2a526vp47ymqnfi@box.shutemov.name>
References: <20221117232304.1544-1-kirill.shutemov@linux.intel.com>
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On Fri, Nov 18, 2022 at 02:23:04AM +0300, Kirill A. Shutemov wrote:
> get_user() expects the pointer to be pointer-to-simple-variable type,
> but sic->data is array of 'unsigned char'. It violates get_user()
> contracts.
> 
> Explicitly take pointer to the first element of the array. It matches
> current behaviour.
> 
> This is preparation for fixing sparse warnings caused by Linear Address
> Masking patchset.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> Cc: "Martin K. Petersen" <martin.petersen@oracle.com>

James, Martin, ping?

It prevents a fix for sparse warnings from applying.

> ---
>  drivers/scsi/scsi_ioctl.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
> index 2d20da55fb64..fdd47565a311 100644
> --- a/drivers/scsi/scsi_ioctl.c
> +++ b/drivers/scsi/scsi_ioctl.c
> @@ -519,7 +519,7 @@ static int sg_scsi_ioctl(struct request_queue *q, fmode_t mode,
>  		return -EFAULT;
>  	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
>  		return -EINVAL;
> -	if (get_user(opcode, sic->data))
> +	if (get_user(opcode, &sic->data[0]))
>  		return -EFAULT;
>  
>  	bytes = max(in_len, out_len);
> -- 
> 2.38.0
> 

-- 
  Kiryl Shutsemau / Kirill A. Shutemov