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Message-Id: <20120124023930.482183636@clark.kroah.org>
Date: Mon, 23 Jan 2012 18:34:54 -0800
From: Greg KH <gregkh@...e.de>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
alan@...rguk.ukuu.org.uk, Haogang Chen <haogangchen@...il.com>,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Mauro Carvalho Chehab <mchehab@...hat.com>
Subject: [074/129] [media] uvcvideo: Fix integer overflow in uvc_ioctl_ctrl_map()
3.2-stable review patch. If anyone has any objections, please let me know.
------------------
Content-Length: 1836
Lines: 53
From: Haogang Chen <haogangchen@...il.com>
commit 806e23e95f94a27ee445022d724060b9b45cb64a upstream.
There is a potential integer overflow in uvc_ioctl_ctrl_map(). When a
large xmap->menu_count is passed from the userspace, the subsequent call
to kmalloc() will allocate a buffer smaller than expected.
map->menu_count and map->menu_info would later be used in a loop (e.g.
in uvc_query_v4l2_ctrl), which leads to out-of-bound access.
The patch checks the ioctl argument and returns -EINVAL for zero or too
large values in xmap->menu_count.
Signed-off-by: Haogang Chen <haogangchen@...il.com>
[laurent.pinchart@...asonboard.com Prevent excessive memory consumption]
Signed-off-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
drivers/media/video/uvc/uvc_v4l2.c | 9 +++++++++
drivers/media/video/uvc/uvcvideo.h | 1 +
2 files changed, 10 insertions(+)
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -58,6 +58,15 @@ static int uvc_ioctl_ctrl_map(struct uvc
break;
case V4L2_CTRL_TYPE_MENU:
+ /* Prevent excessive memory consumption, as well as integer
+ * overflows.
+ */
+ if (xmap->menu_count == 0 ||
+ xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES) {
+ ret = -EINVAL;
+ goto done;
+ }
+
size = xmap->menu_count * sizeof(*map->menu_info);
map->menu_info = kmalloc(size, GFP_KERNEL);
if (map->menu_info == NULL) {
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -113,6 +113,7 @@
/* Maximum allowed number of control mappings per device */
#define UVC_MAX_CONTROL_MAPPINGS 1024
+#define UVC_MAX_CONTROL_MENU_ENTRIES 32
/* Devices quirks */
#define UVC_QUIRK_STATUS_INTERVAL 0x00000001
--
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