Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753189AbdCPSVF (ORCPT ); Thu, 16 Mar 2017 14:21:05 -0400 Received: from foss.arm.com ([217.140.101.70]:37814 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752131AbdCPSVE (ORCPT ); Thu, 16 Mar 2017 14:21:04 -0400 From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org, andreyknvl@google.com Cc: dvyukov@google.com, marc.zyngier@arm.com, christoffer.dall@linaro.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kcc@google.com, syzkaller@googlegroups.com, will.deacon@arm.com, catalin.marinas@arm.com, pbonzini@redhat.com, mark.rutland@arm.com, suzuki.poulose@arm.com, ard.biesheuvel@linaro.org, stable@vger.kernel.org Subject: [PATCH v2 1/3] kvm: arm/arm64: Take mmap_sem in stage2_unmap_vm Date: Thu, 16 Mar 2017 18:20:49 +0000 Message-Id: <1489688451-17520-2-git-send-email-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489688451-17520-1-git-send-email-suzuki.poulose@arm.com> References: <1489688451-17520-1-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1076 Lines: 37 From: Marc Zyngier We don't hold the mmap_sem while searching for the VMAs when we try to unmap each memslot for a VM. Fix this properly to avoid unexpected results. Fixes: commit 957db105c997 ("arm/arm64: KVM: Introduce stage2_unmap_vm") Cc: stable@vger.kernel.org # v3.19+ Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Suzuki K Poulose --- arch/arm/kvm/mmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 962616f..f2e2e0c 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -803,6 +803,7 @@ void stage2_unmap_vm(struct kvm *kvm) int idx; idx = srcu_read_lock(&kvm->srcu); + down_read(¤t->mm->mmap_sem); spin_lock(&kvm->mmu_lock); slots = kvm_memslots(kvm); @@ -810,6 +811,7 @@ void stage2_unmap_vm(struct kvm *kvm) stage2_unmap_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); + up_read(¤t->mm->mmap_sem); srcu_read_unlock(&kvm->srcu, idx); } -- 2.7.4