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.agra...@arm.com>
Cc: Christoffer Dall <christoffer.d...@linaro.org>
Cc: Marc Zyngier <marc.zyng...@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
