Messages in this thread Patch in this message | | | Date | Mon, 23 Jan 2012 18:34:54 -0800 | From | Greg KH <> | Subject | [074/129] [media] uvcvideo: Fix integer overflow in uvc_ioctl_ctrl_map() |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Haogang Chen <haogangchen@gmail.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@gmail.com> [laurent.pinchart@ideasonboard.com Prevent excessive memory consumption] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.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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