On Mon, May 22, 2017 at 12:48:04PM -0700, Guenter Roeck wrote:
> From: Robb Glasser <[email protected]>
>
> 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 <[email protected]>
> [groeck: cherry picked from
> https://source.codeaurora.org/quic/la/kernel/msm-3.10
> commit b7b99e55bc7770187913ed092990852ea52d7892;
> updated subject]
> Signed-off-by: Guenter Roeck <[email protected]>
> ---
> Fixes CVE-2017-0627.
>
Please do not apply this patch. It is buggy.
Guenter
> 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;
> +
> if (mutex_lock_interruptible(&chain->ctrl_mutex))
> return -ERESTARTSYS;
>
Hi Guenter,
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 <[email protected]>
> >
> > 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 <[email protected]>
> > [groeck: cherry picked from
> >
> > https://source.codeaurora.org/quic/la/kernel/msm-3.10
> > commit b7b99e55bc7770187913ed092990852ea52d7892;
> > updated subject]
> >
> > Signed-off-by: Guenter Roeck <[email protected]>
> > ---
> > 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;
> > +
> >
> > if (mutex_lock_interruptible(&chain->ctrl_mutex))
> > return -ERESTARTSYS;
--
Regards,
Laurent Pinchart
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 <[email protected]>
> >>
> >> 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 <[email protected]>
> >> [groeck: cherry picked from
> >>
> >> https://source.codeaurora.org/quic/la/kernel/msm-3.10
> >> commit b7b99e55bc7770187913ed092990852ea52d7892;
> >> updated subject]
> >>
> >> Signed-off-by: Guenter Roeck <[email protected]>
> >> ---
> >> 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
On Wed, Jun 28, 2017 at 09:18:37PM +0300, Laurent Pinchart wrote:
> 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 <[email protected]>
> > >>
> > >> 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 <[email protected]>
> > >> [groeck: cherry picked from
> > >>
> > >> https://source.codeaurora.org/quic/la/kernel/msm-3.10
> > >> commit b7b99e55bc7770187913ed092990852ea52d7892;
> > >> updated subject]
> > >>
> > >> Signed-off-by: Guenter Roeck <[email protected]>
> > >> ---
> > >> 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;
>
I currently have this:
@@ -2004,6 +2004,13 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
goto done;
}
+ /* validate that the user provided bit-size and offset is valid */
+ if ((mapping->size > 32) ||
+ ((mapping->offset + mapping->size) > (ctrl->info.size * 8))) {
+ ret = -EINVAL;
+ goto done;
+ }
+
list_for_each_entry(map, &ctrl->info.mappings, list) {
if (mapping->id == map->id) {
uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', "
This version originates from Richard Simmons. Copying him to see if he wants
to submit it himself.
Guenter