Re: [PATCH v8 14/21] mm/mmap: Avoid zeroing vma tree in mmap_region()

[Bert Karwatzki]

Am Dienstag, dem 01.10.2024 um 09:49 +0100 schrieb Lorenzo Stoakes:
> On Tue, Oct 01, 2024 at 10:38:35AM GMT, Bert Karwatzki wrote:
> > Am Dienstag, dem 01.10.2024 um 09:02 +0100 schrieb Lorenzo Stoakes:
> > > On Tue, Oct 01, 2024 at 04:34:00AM GMT, Bert Karwatzki wrote:
> > > > I just noticed (via a bisect between v6.11 and v6.12-rc1) that this patch
> > > > (commit f8d112a4e657 in linux-next tree) leads to a severe memory corruption
> > > > error under these (rather rare) circumstances:
> > > > 1. Start a 32bit windows game via steam (which uses proton, steam's version of wine)
> > > > 2. When starting the game you the proton version used has to be updated
> > >
> > > Yikes. Thanks for the report, very very much appreciated. Will look into
> > > this as Liam is out until next week.
> > >
> > > How repro is this? Is it consistent?
> >
> > Reproducability is 100%, only the method is weird, you have to switch to an
> > older version of proton in the steam settings of the game, start the game and
> > then switch back to the new version and start the game again.
> >  It might also be possible using standard wine and repeatedly upgrading and
> > downgrading wine and (I have not tried this, yet ...)
> >
>
> OK that's good.
>
> Actually a quick one if you have a sec - could you try the same thing with tip
> of Linus's tree?
>
> This will help eliminate any other possible cause.
>
> Thanks!
>
> >
I first noticed the bug unsing linux-next-20240926, it's also present in v6.12-
rc1 (hence the bisection), but I can try linux-next or linux-torvald master,
too.

Bert Karwatzki