Code: static int cdrom_ioctl_drive_status(struct cdrom_device_info *cdi,
		unsigned long arg)
{
	cd_dbg(CD_DO_IOCTL, "entering CDROM_DRIVE_STATUS\n");

	if (!(cdi->ops->capability & CDC_DRIVE_STATUS))
		return -ENOSYS;
 	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))
 		return -EINVAL;
 	return cdrom_slot_status(cdi, arg);
 }

Vulnerability Type: +Info 
CWE ID: CWE-200
Summary: An issue was discovered in the Linux kernel before 4.18.6. An information leak in cdrom_ioctl_drive_status in drivers/cdrom/cdrom.c could be used by local attackers to read kernel memory because a cast from unsigned long to int interferes with bounds checking. This is similar to CVE-2018-10940.
Commit Message: cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status

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@intel.com>
Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>