From 48f2825abc65943437033adfd05b59e287ea3bfd Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 16 Mar 2017 18:20:49 +0000 Subject: [PATCH] arm/arm64: KVM: Take mmap_sem in stage2_unmap_vm commit 90f6e150e44a0dc3883110eeb3ab35d1be42b6bb upstream. 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") Reviewed-by: Christoffer Dall Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- 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 a5265ed..089f9df16 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