RE: [char-misc v2] mei: trace: treat reg parameter as string
From: Usyskin, Alexander
Date: Thu Jan 08 2026 - 03:20:25 EST
> Subject: Re: [char-misc v2] mei: trace: treat reg parameter as string
>
> On Thu, Jan 08, 2026 at 07:42:22AM +0000, Usyskin, Alexander wrote:
> > > Subject: Re: [char-misc v2] mei: trace: treat reg parameter as string
> > >
> > > On Thu, Jan 08, 2026 at 08:57:02AM +0200, Alexander Usyskin wrote:
> > > > Use the string wrapper to check sanity of the reg parameters,
> > > > store it value independently and prevent internal kernel data leaks.
> > > > Trace subsystem refuses to emit event with plain char*,
> > > > without the wrapper.
> > > >
> > > > Cc: stable@xxxxxxxxxxxxxxx
> > >
> > > Does this really fix a bug? If not, there's no need for cc: stable or:
> > >
> > > > Fixes: a0a927d06d79 ("mei: me: add io register tracing")
> > >
> > > That line as well.
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > Without this patch the events are not emitted at all, they are dropped
> > by trace security checker.
>
> Ah, again, that was not obvious at all from the changelog. Perhaps
> reword it a bit? How has this ever worked?
>
This security hardening was introduced way after the initial commit
and the breakage went unnoticed for some time, unfortunately.
- -
Thanks,
Sasha