Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752511AbeADSYt (ORCPT + 1 other); Thu, 4 Jan 2018 13:24:49 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:36258 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbeADSYp (ORCPT ); Thu, 4 Jan 2018 13:24:45 -0500 From: Punit Agrawal To: kvmarm@lists.cs.columbia.edu Cc: Punit Agrawal , linux-kernel@vger.kernel.org, Christoffer Dall , Marc Zyngier Subject: [PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at Stage 2 Date: Thu, 4 Jan 2018 18:24:33 +0000 Message-Id: <20180104182433.3790-1-punit.agrawal@arm.com> X-Mailer: git-send-email 2.15.1 X-ARM-No-Footer: FoSSMail Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 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 Cc: Christoffer Dall Cc: Marc Zyngier --- 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