[PATCH v2 0/4] mm: Avoid sharing high VMA flag bits

[Andrew Morton]

On Wed,  7 May 2025 15:09:56 +0200 Florent Revest <revest at chromium.org> wrote:

> The first patch of this series is a straightforward attempt at fixing this
> specific bug by changing the bit used by VM_UFFD_MINOR. I cc-ed stable on that
> one and I expect it to not be all too controversial.
> 
> The rest of the series however is a more zealous refactoring and likely to be
> more contentious... :) Since this bug looks like a near miss which could have
> been quite severe in terms of security, I think it's worth trying to simplify
> the high VMA flag bits code. I tried to consolidate around the current usage of
> VM_HIGH_ARCH_* macros but I'm not sure if this is the preferred approach here. I
> really don't feel strongly about those refactorings so this is more of a
> platform for discussion for people with more mm background, I'll be more than
> happy to respin a v2!

It's best to avoid combining backportable bugfixes with regular
development patches, please.  These two categories differ a lot in
their timing and version-targeting.

I'll queue the [1/N] bugfix targeted at 6.15 and -stable, thanks.