From: Haogang Chen Date: Tue, 29 Nov 2011 21:32:25 +0000 (-0300) Subject: uvcvideo: Fix integer overflow in uvc_ioctl_ctrl_map() X-Git-Tag: v3.2.2~56 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=053ae10f55886546a5974d9d75a041ff2cea0cbd;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git uvcvideo: Fix integer overflow in uvc_ioctl_ctrl_map() 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 [laurent.pinchart@ideasonboard.com Prevent excessive memory consumption] Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c index dadf11f..cf7788f 100644 --- 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_video_chain *chain, 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) { diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h index 4c1392e..bc446ba 100644 --- 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