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Date:   Tue, 4 Jul 2023 09:18:08 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     Suren Baghdasaryan <surenb@google.com>,
        Linux regressions mailing list <regressions@lists.linux.dev>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
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Subject: Re: Fwd: Memory corruption in multithreaded user space program
 while calling fork
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On Tue, 4 Jul 2023 09:00:19 +0100 Greg KH <gregkh@linuxfoundation.org> wrote:

> > > > > Thanks! I'll investigate this later today. After discussing with
> > > > > Andrew, we would like to disable CONFIG_PER_VMA_LOCK by default until
> > > > > the issue is fixed. I'll post a patch shortly.
> > > >
> > > > Posted at: https://lore.kernel.org/all/20230703182150.2193578-1-surenb@google.com/
> > >
> > > As that change fixes something in 6.4, why not cc: stable on it as well?
> > 
> > Sorry, I thought since per-VMA locks were introduced in 6.4 and this
> > patch is fixing 6.4 I didn't need to send it to stable for older
> > versions. Did I miss something?
> 
> 6.4.y is a stable kernel tree right now, so yes, it needs to be included
> there :)

I'm in wait-a-few-days-mode on this.  To see if we have a backportable
fix rather than disabling the feature in -stable.