RE: [PATCH 1/2] scsi: Fix get_user() in call sg_scsi_ioctl()

From: David Laight
Date: Wed Nov 16 2022 - 17:40:24 EST


From: Kirill A. Shutemov
> Sent: 16 November 2022 00:44
>
> 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.
>
> Cast it explicitly to 'unsigned char __user *'. 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@xxxxxxxxxxxxxxx>
> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> ---
> 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..72b3ab5137b8 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, (unsigned char __user *)sic->data))

Using &sic->data[0] should work and is much nicer than the cast.

David

> return -EFAULT;
>
> bytes = max(in_len, out_len);
> --
> 2.38.0

-
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