Hi Guenter, On Wednesday 28 Jun 2017 20:59:17 Laurent Pinchart wrote: > On Wednesday 28 Jun 2017 07:36:43 Guenter Roeck wrote: > > On Mon, May 22, 2017 at 12:48:04PM -0700, Guenter Roeck wrote: > >> From: Robb Glasser <rglasser@xxxxxxxxxx> > >> > >> The size of uvc_control_mapping is user controlled leading to a > >> potential heap overflow in the uvc driver. This adds a check to verify > >> the user provided size fits within the bounds of the defined buffer > >> size. > >> > >> Signed-off-by: Robb Glasser <rglasser@xxxxxxxxxx> > >> [groeck: cherry picked from > >> > >> https://source.codeaurora.org/quic/la/kernel/msm-3.10 > >> commit b7b99e55bc7770187913ed092990852ea52d7892; > >> updated subject] > >> > >> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> > >> --- > >> Fixes CVE-2017-0627. > > > > Please do not apply this patch. It is buggy. > > I apologize for not noticing the initial patch, even if it looks like it was > all for the best. Will you send a new version ? > > >> drivers/media/usb/uvc/uvc_ctrl.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c > >> b/drivers/media/usb/uvc/uvc_ctrl.c index c2ee6e39fd0c..252ab991396f > >> 100644 > >> --- a/drivers/media/usb/uvc/uvc_ctrl.c > >> +++ b/drivers/media/usb/uvc/uvc_ctrl.c > >> @@ -1992,6 +1992,9 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain > >> *chain, > >> if (!found) > >> return -ENOENT; > >> > >> + if (ctrl->info.size < mapping->size) > >> + return -EINVAL; > >> + By the way, I believe the right fix should be if (mapping->offset + mapping->size > ctrl->info.size * 8) return -EINVAL; Both mapping->offset and mapping->size are 8-bit integers, so there's no risk of overflow in the addition. If we want to safeguard against a possible future bug if the type of the fields change, we could add if (mapping->offset + mapping->size < mapping->offset) return -EINVAL; > >> if (mutex_lock_interruptible(&chain->ctrl_mutex)) > >> return -ERESTARTSYS; -- Regards, Laurent Pinchart
