From: Scott Bauer <scott.bauer@intel.com>
Date: Thu, 26 Apr 2018 17:51:08 +0000 (-0600)
Subject: cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b8c0e15469bab732065e64f7dffadab0b7103990;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status

commit 8f3fafc9c2f0ece10832c25f7ffcb07c97a32ad4 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 07b77fb102a1..987e8f503522 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2536,7 +2536,7 @@ 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);
 }