Re: [PATCH v3 4/4] media: uvcvideo: RFC: Convert allow_privacy_override into Kconfig

[Ricardo Ribalda <ribalda@chromium.org>]

Hi Gergo

On Thu, 19 Mar 2026 at 12:50, Gergo Koteles <soyer@irl.hu> wrote:
>
> Hi Ricardo,
>
> On Wed, 2026-03-18 at 15:57 +0100, Ricardo Ribalda wrote:
> > Hi Greg
> >
> > On Wed, 18 Mar 2026 at 15:17, Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Mon, Mar 16, 2026 at 01:34:47PM +0000, Ricardo Ribalda wrote:
> > > > This patch is just shared for discussion purposes! Do not land.
> > > >
> > > > In a perfect world, after a deprecation process, we will be able to
> > > > remove allow_privacy_override and block all privacy related controls.
> > >
> > > Why add something you are only going to remove in the future?  What has
> > > changed to require this now, and will change in the future to make it
> > > not needed?
> >
> > Currently, any application with camera access can manipulate the
> > privacy LED. I believe this is a security flaw; ideally, the kernel
> > should block all such controls by default.
> >
> > However, blocking these controls immediately might be seen as a
> > regression for certain users. I added allow_privacy_override to:
> > - Prevent breaking existing workflows immediately upon a kernel update.
> > - Give users time to report why they still need manual LED control.
> >
> > The goal is to gather these use cases over the next 1–2 years. Once we
> > understand the legitimate needs, we can either implement a proper
> > specialized mechanism for them or move the toggle to a Kconfig option
> > for those who explicitly need to opt-in to the old behavior or simply
> > remove the toggle altogether.
> >
> > For the record, identified use cases so far:
> > - Old hardware with red LEDs that reflect on glasses. (Likely a dying niche).
>
> Older Logitech cameras, like the c920, have fairly large LEDs that can
> be reflective, and it's hard to cover them up aesthetically. Laurent
> wrote [1] that's why Logitech added this functionality a long time ago.
>
> You can find old Logitech software for Windows that still allows you to
> turn off the LEDs [2]. I tried it in a Win10 VM and it really works.

In the same link you will find that Logitech has removed that option
in newer version of the Logitech software and a "Official Logitech
Representative" says that:

```Please be informed that there is no way to disable the blue led
light on the webcam as that is the indicator that the webcam is active
and its mainly for security purpose.```

Other users say that
```I would not buy a webcam with an led that can be switched off and
that can watch me without any chance noticing it.```

This is definitely a requested feature by the users and it seems even
the vendor has realized that the security risk of a "stealth" camera
outweighs the benefit of turning off the LED.

>
> The c920 is a very popular camera, still available in stores today.
> Amazon says it sells 12k of them per month [3].
>
> 1:
> https://lore.kernel.org/all/20251119041907.GH10711@pendragon.ideasonboard.com/
>
> 2: https://www.reddit.com/r/logitech/comments/v641x6/comment/nr22zo7/
>
> 3: https://www.amazon.com/s?k=logitech+c920
>
> > - Using cameras as baby monitors where the LED disturbs sleep.
>
> And pet cameras and surveillance cameras don't need LEDs either.

Agree. All surveillance cameras.

All those special cases can use the allow_privacy_override parameter
until we find a good way to handle their use case.

>
> > (Arguably solvable with a piece of tape on the LED, but still a
> > reported use case).
> >
>
> Furthermore, if we filter these two Logitech XUs, we could then add the
> similar XUs of the camera modules in laptops and this could be an ever-
> growing list.

That is the goal, to have a list as comprehensive as possible.

>
> >
> Best regards,
> Gergo Koteles



-- 
Ricardo Ribalda