Re: [PATCH] x86/mm: avoid a reclaiming allocation in pud_free_pmd_page()

[Mikhail Gavrilov]

Hi,

The lock cycle this patch breaks has meanwhile reached released stable
kernels: d5d8b8662e6e ("x86/mm/pat: Acquire init_mm read lock on
attribute changes to avoid UAF") went out in 7.2.7 and 6.18.53 on
Sep 21. Both trees already carry 26444eb71465 ("mm/vmalloc: acquire
init_mm lock on huge vmap to avoid ptdump UAF"), and pud_free_pmd_page()
there still allocates with GFP_KERNEL under the init_mm lock, so the
cycle quoted in the patch exists there too, not only in 7.3-rc.

The patch still applies cleanly to current mainline and next-20260922,
and the reproducer below the scissors of the original mail works
unchanged.

Dave, could this go in through x86/urgent for 7.3? Lorenzo, since the
rule it applies comes from your series, a review from you would help.
If either of you would rather fix it differently, I am happy to respin.

-- 
Thanks,
Mikhail