Re: x86/mm: Finishing off the fix for a should_flush_tlb race

[Stephen Dolan]

On Tue, 17 Feb 2026 at 15:20, Seth Forshee <sforshee@xxxxxxxxxx> wrote:
> > I wanted to check on the status of the stable patches, since I see the
> > upstream fix went into 6.18 but there's still no fix in the 6.12 stable
> > tree. We've been seeing segfaults during a test case with 6.12, and
> > after bisecting we found that reverting both "x86/mm: Eliminate window
> > where TLB flushes may be inadvertently skipped" and "x86/mm/tlb: Only
> > trim the mm_cpumask once a second" seems to get rid of the segfaults.
> > I'll try to get some testing with the proposed stable patch today.

Hmm, ok. I posted the patch to stable@xxxxxxxxxxxxxxx a while ago but
it looks like it never got merged. Does this patch fix the issue for
you?

    https://lore.kernel.org/stable/CAHDw0oE0334gEJ=ga1PAnZ3Av8+tFkKF-MJCF7Jj3i6pBVJvFQ@xxxxxxxxxxxxxx/

Stephen