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

[Gergo Koteles]

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@xxxxxxxxxxxxxxxxxxx> 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.

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@xxxxxxxxxxxxxxxxxxxxxxxxxx/

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.

> (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.

> 
Best regards,
Gergo Koteles