Messages in this thread Patch in this message | | | From | Punit Agrawal <> | Subject | [PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at Stage 2 | Date | Thu, 4 Jan 2018 18:24:33 +0000 |
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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: ad361f093c1e31d ("KVM: ARM: Support hugetlbfs backed huge pages") Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> --- virt/kvm/arm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index b4b69c2d1012..9dea96380339 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1310,7 +1310,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, return -EFAULT; } - if (is_vm_hugetlb_page(vma) && !logging_active) { + if (vma_kernel_pagesize(vma) == PMD_SIZE && !logging_active) { hugetlb = true; gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; } else { -- 2.15.1
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