vm_mixed_zeropage_allowed() validates zeropage insertion into VM_MIXEDMAP VMAs. No in-tree user needs to insert the huge zero page through vmf_insert_pfn_pmd(). Return VM_FAULT_SIGBUS if vmf_insert_pfn_pmd() is asked to map it. Link: https://lore.kernel.org/linux-mm/f76beaf8-351a-4b22-b362-a945a5e1af6a@kernel.org/ Suggested-by: Kiryl Shutsemau Suggested-by: David Hildenbrand Signed-off-by: Lance Yang --- mm/huge_memory.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index bfd972b997f9..c02f21ce4f4c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1728,6 +1728,9 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, unsigned long pfn, (VM_PFNMAP|VM_MIXEDMAP)); BUG_ON((vma->vm_flags & VM_PFNMAP) && vma_is_cow_mapping(vma)); + if (unlikely(is_huge_zero_pfn(pfn))) + return VM_FAULT_SIGBUS; + pfnmap_setup_cachemode_pfn(pfn, &pgprot); return insert_pmd(vma, addr, vmf->pmd, fop, pgprot, write); -- 2.39.3 (Apple Git-146)