Re: [PATCH 0/4] mm: avoid losing atomic VMA flags

[Andrew Morton]

On Fri, 23 Oct 2026 14:47:26 +0100 "Lorenzo Stoakes (ARM)" <ljs@xxxxxxxxxx> wrote:

> Since commit 2ab7f1bbafc9 ("mm/madvise: allow guard page install/remove
> under VMA lock"), VMA_MAYBE_GUARD_BIT can be set atomically under the VMA
> read lock.
> 
> However, a number of places wrongly assume the flags are stable under the
> read lock, which can cause stale atomic VMA flags to overwrite existing
> valid ones.
> 
> Additionally, one case in which VMA_SOFTDIRTY_BIT was overwritten is also
> addressed.
> 
> This series addresses each of these, while keeping the logic inline with
> existing conventions.

Added to mm-unstable thanks.

> Each patch in this series is a hotfix.

The fixes continue to pour in.  Right now I'm adding everything to the
tail of mm-unstable while patiently for Linus to merge our stuff.

Once that happens I'll assemble the second-week merge-window material
into mm-stable and I'll spill the recently-arriving cc:stable material
into mm-hotfixes.

I don't think it matters whether cc:stable material is upstreamed in
7.4-rc1 or in 7.4-rc3 - rather than rushing it in I'd prefer to give it
a week or two baking time.