3.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: Marc Zyngier <[email protected]> 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 <[email protected]> Cc: Eric Auger <[email protected]> Reviewed-by: Christoffer Dall <[email protected]> [ Handle dirty page logging failure case ] Signed-off-by: Suzuki K Poulose <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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; }
