From 806e23e95f94a27ee445022d724060b9b45cb64a Mon Sep 17 00:00:00 2001 From: Haogang Chen Date: Tue, 29 Nov 2011 18:32:25 -0300 Subject: [PATCH] [media] uvcvideo: Fix integer overflow in uvc_ioctl_ctrl_map() 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 Cc: stable@kernel.org Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_v4l2.c | 9 +++++++++ drivers/media/video/uvc/uvcvideo.h | 1 + 2 files changed, 10 insertions(+) diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c index b1dc3e507fc1..2ae4f880ea05 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 e9c19f53e4a1..67f88d85bb16 100644 --- a/drivers/media/video/uvc/uvcvideo.h +++ b/drivers/media/video/uvc/uvcvideo.h @@ -114,6 +114,7 @@ /* 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 -- 2.20.1