[PATCH v1 10/36] mm: sanity-check maximum folio size in folio_set_order()
From: David Hildenbrand <hidden>
Date: 2025-08-27 22:05:19
Also in:
dri-devel, intel-gfx, io-uring, kvm, linux-arm-kernel, linux-crypto, linux-ide, linux-iommu, linux-kselftest, linux-mips, linux-mm, linux-mmc, linux-riscv, linux-s390, linux-scsi, lkml, virtualization
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
Let's sanity-check in folio_set_order() whether we would be trying to create a folio with an order that would make it exceed MAX_FOLIO_ORDER. This will enable the check whenever a folio/compound page is initialized through prepare_compound_head() / prepare_compound_page(). Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: David Hildenbrand <redacted> --- mm/internal.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/mm/internal.h b/mm/internal.h
index 45da9ff5694f6..9b0129531d004 100644
--- a/mm/internal.h
+++ b/mm/internal.h@@ -755,6 +755,7 @@ static inline void folio_set_order(struct folio *folio, unsigned int order) { if (WARN_ON_ONCE(!order || !folio_test_large(folio))) return; + VM_WARN_ON_ONCE(order > MAX_FOLIO_ORDER); folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order; #ifdef NR_PAGES_IN_LARGE_FOLIO
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2.50.1