diff options
| author | David Hildenbrand <david@redhat.com> | 2025-09-01 17:03:28 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-21 14:22:02 -0700 |
| commit | 646b67d575897dc656b07446e23e756d54e49828 (patch) | |
| tree | 30d652e19b5601c6501d53167ca488c01397a32e | |
| parent | 0bf2edf041dcb0b304a8dbda8c699771d5a245d2 (diff) | |
mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages()
Let's reject unreasonable folio sizes early, where we can still fail.
We'll add sanity checks to prepare_compound_head/prepare_compound_page
next.
Is there a way to configure a system such that unreasonable folio sizes
would be possible? It would already be rather questionable.
If so, we'd probably want to bail out earlier, where we can avoid a WARN
and just report a proper error message that indicates where something went
wrong such that we messed up.
Link: https://lkml.kernel.org/r/20250901150359.867252-8-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/memremap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/memremap.c b/mm/memremap.c index b0ce0d8254bd..a2d4bb88f64b 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -275,6 +275,9 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) if (WARN_ONCE(!nr_range, "nr_range must be specified\n")) return ERR_PTR(-EINVAL); + if (WARN_ONCE(pgmap->vmemmap_shift > MAX_FOLIO_ORDER, + "requested folio size unsupported\n")) + return ERR_PTR(-EINVAL); switch (pgmap->type) { case MEMORY_DEVICE_PRIVATE: |