Commit 90f6e150 authored Mar 16, 2017 by Marc Zyngier

arm/arm64: KVM: Take mmap_sem in stage2_unmap_vm



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 957db105 ("arm/arm64: KVM: Introduce stage2_unmap_vm")
Cc: stable@vger.kernel.org # v3.19+
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>

parent 955a3fc6

arch/arm/kvm/mmu.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -803,6 +803,7 @@ void stage2_unmap_vm(struct kvm *kvm)
		int idx;

		idx = srcu_read_lock(&kvm->srcu);
		down_read(&current->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(&current->mm->mmap_sem);
		srcu_read_unlock(&kvm->srcu, idx);
		}