ACK: [CVE-2018-16658][Trusty][Bionic][SRU][PATCH 1/1] cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status

[Kleber Souza]

On 10/03/18 08:29, Po-Hsu Lin wrote:
> From: Scott Bauer <scott.bauer at intel.com>
> 
> CVE-2018-16658
> 
> Like d88b6d04: "cdrom: information leak in cdrom_ioctl_media_changed()"
> 
> There is another cast from unsigned long to int which causes
> a bounds check to fail with specially crafted input. The value is
> then used as an index in the slot array in cdrom_slot_status().
> 
> Signed-off-by: Scott Bauer <scott.bauer at intel.com>
> Signed-off-by: Scott Bauer <sbauer at plzdonthack.me>
> Cc: stable at vger.kernel.org
> Signed-off-by: Jens Axboe <axboe at kernel.dk>
> (cherry picked from commit 8f3fafc9c2f0ece10832c25f7ffcb07c97a32ad4)
> Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

> ---
>  drivers/cdrom/cdrom.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
> index cbee2e7..f0534a4 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -2542,7 +2542,7 @@ static int cdrom_ioctl_drive_status(struct cdrom_device_info *cdi,
>  	if (!CDROM_CAN(CDC_SELECT_DISC) ||
>  	    (arg == CDSL_CURRENT || arg == CDSL_NONE))
>  		return cdi->ops->drive_status(cdi, CDSL_CURRENT);
> -	if (((int)arg >= cdi->capacity))
> +	if (arg >= cdi->capacity)
>  		return -EINVAL;
>  	return cdrom_slot_status(cdi, arg);
>  }
>