Re:Re: [PATCH] usb: typec: ucsi: acpi: Check ACPI companion before use

[jiale yao]

Hi Huang,

At 2026-10-20 10:27:07, "Huang Wei" <huangwei@xxxxxxxxxx> wrote:
>Hi Jiale,
>
>A heads-up on the history here: a functionally identical patch was
>posted in September by Yogesh Gaur:
>
>  https://lore.kernel.org/linux-usb/20260920090711.300-1-yogeshgaur.83@xxxxxxxxx/
>
>Greg declined it on the grounds that the only realistic way to reach
>probe without an ACPI companion is the driver_override + sysfs bind
>path, which is a deliberate root action, with the resulting OOPS
>being identifiable by the taint flag - "if userspace does it, it
>deserves the pieces the kernel ends up in":
>
>  https://lore.kernel.org/linux-usb/2026092130-thong-secrecy-1dd4@gregkh/
>
>The open question left from that thread was whether syzbot still
>exercises the override+bind path - if it does and keeps generating
>these reports, that would be an argument for taking the guard anyway.
>Yogesh's version referenced a syzbot report; yours does not, so I
>can't tell from the patch whether you hit the same report or found
>this independently.

Thanks for your reply.
The bug was found by my static analysis tool, which is currently under development.

>
>For what it's worth, the fix itself is fine - I reviewed Yogesh's
>version at the time, including checking that this is the only
>unchecked ACPI_COMPANION() in drivers/usb/typec/. Whether it lands
>is purely a policy call at this point.
>
>Thanks,
>Huang Wei

Jiale