4.9-stable review patch. If anyone has any objections, please let me know.
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From: Punit Agrawal punit.agrawal@arm.com
commit c507babf10ead4d5c8cca704539b170752a8ac84 upstream.
KVM only supports PMD hugepages at stage 2 but doesn't actually check that the provided hugepage memory pagesize is PMD_SIZE before populating stage 2 entries.
In cases where the backing hugepage size is smaller than PMD_SIZE (such as when using contiguous hugepages), KVM can end up creating stage 2 mappings that extend beyond the supplied memory.
Fix this by checking for the pagesize of userspace vma before creating PMD hugepage at stage 2.
Fixes: 66b3923a1a0f77a ("arm64: hugetlb: add support for PTE contiguous bit") Signed-off-by: Punit Agrawal punit.agrawal@arm.com Cc: Marc Zyngier marc.zyngier@arm.com Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Signed-off-by: Christoffer Dall christoffer.dall@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm/kvm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1284,7 +1284,7 @@ static int user_mem_abort(struct kvm_vcp return -EFAULT; }
- if (is_vm_hugetlb_page(vma) && !logging_active) { + if (vma_kernel_pagesize(vma) && !logging_active) { hugetlb = true; gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; } else {