3.18-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 90f6e150e44a0dc3883110eeb3ab35d1be42b6bb ]
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 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: Sasha Levin sashal@kernel.org --- 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 e506389d02fb..017d6d1e1766 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -760,6 +760,7 @@ 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); @@ -767,6 +768,7 @@ 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); }