| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.10 011/110] arm/arm64: KVM: Take mmap_sem in stage2_unmap_vm | Date | Mon, 10 Apr 2017 18:42:02 +0200 |
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4.10-stable review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier <marc.zyngier@arm.com>
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 <cdall@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/arm/kvm/mmu.c | 2 ++ 1 file changed, 2 insertions(+)
--- 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); }
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