* Re: [PATCH v2] mm/secretmem: don't allow highmem folios
[not found] <20260717-secretmem-highmem-v2-1-1f1a961ca91e@google.com>
@ 2026-07-18 10:49 ` Mike Rapoport
0 siblings, 0 replies; only message in thread
From: Mike Rapoport @ 2026-07-18 10:49 UTC (permalink / raw)
To: Brendan Jackman
Cc: Andrew Morton, David Hildenbrand, Lorenzo Stoakes,
Liam R. Howlett, Vlastimil Babka, Suren Baghdasaryan,
Michal Hocko, linux-mm, linux-kernel, brendan.jackman
On Fri, Jul 17, 2026 at 09:48:59AM +0000, Brendan Jackman wrote:
> secretmem_fault() allocates a folio with GFP_HIGHUSER and then calls
> set_direct_map_invalid_noflush() without checking folio_test_highmem().
> This causes a warning and process crash (vibe-coded reproducer in Link
> below):
...
> Link: https://github.com/bjackman/limmat-kernel-nix/commit/7b2acba2d3a5ef01400d493a155beb1d135b6bb5
> Suggested-by: Andrew Morton <akpm@linux-foundation.org>
> Link: https://lore.kernel.org/all/20260704192603.40aa80cf9242b77aa75e8d8d@linux-foundation.org/
> Fixes: 1507f51255c9f ("mm: introduce memfd_secret system call to create "secret" memory areas")
> Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
--
Sincerely yours,
Mike.
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