Re: [PATCH] media: Fix invalid link creation when source entity has 0 pads

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Tue, Mar 25, 2025 at 06:05:00PM -0400, Gabriel wrote:
> Hi Ricardo,
> 
> > I cannot reach that URL
> I was unable to access the URL from my email client when I initially
> sent the email, but a couple of hours later, I was able to. Initially,
> copying and pasting the URL into the browser provided a workaround.
> 
> > Shouldn't it be?:
> > Fixes: 4ffc2d89f38a ("[media] uvcvideo: Register subdevices for each entity")
> You're right, I incorrectly referenced the wrong commit. However, I’m
> not certain if it should reference a96aa5342d57 (Fixes: a96aa5342d57 -
> '[media] uvcvideo: Ignore entities for terminals with no supported
> format') as it's the latest commit affecting the line I'm changing or
> the one you mentioned.
> 
> > Shouldn't source->num_pads be the same as remote->num_pads?
> The fuzzer (Syzkaller) that triggered the warning appears to have
> encountered a case where source->num_pads and remote->num_pads were
> different. When analyzing the case in GDB, remote->num_pads was 1,
> while source->num_pads was 0.

This seems like the real bug that should be fixed.

> > Are you sure that your kernel does not contain?
> > https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/media/usb/uvc/uvc_entity.c?id=41ddb251c68ac75c101d3a50a68c4629c9055e4c
> Yes, it should be included since I am running the upstream kernel.

-- 
Regards,

Laurent Pinchart