| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.18 070/124] arm/arm64: KVM: Take mmap_sem in kvm_arch_prepare_memory_region | Date | Thu, 20 Apr 2017 08:35:45 +0200 |
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3.18-stable review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier <marc.zyngier@arm.com>
commit 72f310481a08db821b614e7b5d00febcc9064b36 upstream.
We don't hold the mmap_sem while searching for VMAs (via find_vma), in kvm_arch_prepare_memory_region, which can end up in expected failures.
Fixes: commit 8eef91239e57 ("arm/arm64: KVM: map MMIO regions at creation time") Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Eric Auger <eric.auger@rehat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> [ Handle dirty page logging failure case ] 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 | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1407,6 +1407,7 @@ int kvm_arch_prepare_memory_region(struc (KVM_PHYS_SIZE >> PAGE_SHIFT)) return -EFAULT; + down_read(¤t->mm->mmap_sem); /* * A memory region could potentially cover multiple VMAs, and any holes * between them, so iterate over all of them to find out if we can map @@ -1464,6 +1465,8 @@ int kvm_arch_prepare_memory_region(struc else stage2_flush_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); + + up_read(¤t->mm->mmap_sem); return ret; }
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