Re: [PATCH 0/4] mm/mempolicy: kernel_migrate_pages: fix race between security checks and suid exec

From: Oleg Nesterov

Date: Sun May 24 2026 - 15:36:43 EST


On 05/24, Oleg Nesterov wrote:
>
> Hopefully sashiko.dev will take a look too ;)

See https://sashiko.dev/#/patchset/ahMt6xyUNnacZU8-%40redhat.com
Thanks Sashiko, let me reply.

As for reply to 3/4:

I honestly think this is not a problem... but a) I will think
again, and b) I rely on review from mm experts anyway.

The main motivation for this patch is that we can create a common
helper for find_mm_struct() and kernel_migrate_pages(), but it is
not strictly necessary.

As for reply to 4/4:

Yes! And I have already mentioned this in 0/4 and in the previous
discussions.

Plus (say) proc_coredump_filter_write() which relies on the open-time
checks and don't use ptrace_may_access() at all. This looks wrong.

But this need other changes/discussions, so I think we can ignore this
comment.

Oleg.