From mboxrd@z Thu Jan 1 00:00:00 1970 From: suzuki.poulose@arm.com (Suzuki K Poulose) Date: Tue, 14 Mar 2017 14:52:32 +0000 Subject: [PATCH 1/3] kvm: arm/arm64: Take mmap_sem in stage2_unmap_vm In-Reply-To: <1489503154-20705-1-git-send-email-suzuki.poulose@arm.com> References: <1489503154-20705-1-git-send-email-suzuki.poulose@arm.com> Message-ID: <1489503154-20705-2-git-send-email-suzuki.poulose@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 at vger.kernel.org # v3.19+ Cc: 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