From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
Sashiko AI review <sashiko-bot@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
David Hildenbrand <david@kernel.org>,
Michal Hocko <mhocko@suse.com>, Mike Rapoport <rppt@kernel.org>,
Peter Xu <peterx@redhat.com>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@kernel.org>,
Balbir Singh <balbirs@nvidia.com>,
Andrew Morton <akpm@linux-foundation.org>,
Kiryl Shutsemau <kas@kernel.org>
Subject: Re: [PATCH 5.15.y] userfaultfd: gate must_wait writability check on pte_present()
Date: Fri, 3 Jul 2026 22:05:17 -0400 [thread overview]
Message-ID: <2026070315-stable-reply-0023@kernel.org> (raw)
In-Reply-To: <20260702154900.975365-1-kas@kernel.org>
On Thu, Jul 02, 2026 at 16:49:00 +0100, Kiryl Shutsemau wrote:
> userfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE
> without taking the page table lock and then apply pte_write() /
> huge_pte_write() to it. Those accessors decode bits from the present
> encoding only; on a swap or migration entry they read the offset bits that
> happen to share the same position and return an undefined result.
Queued for 5.15.y, thanks!
--
Thanks,
Sasha
prev parent reply other threads:[~2026-07-04 2:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-02 12:52 FAILED: patch "[PATCH] userfaultfd: gate must_wait writability check on" failed to apply to 5.15-stable tree gregkh
2026-07-02 15:49 ` [PATCH 5.15.y] userfaultfd: gate must_wait writability check on pte_present() Kiryl Shutsemau
2026-07-04 2:05 ` Sasha Levin [this message]
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