In the Linux kernel, the following vulnerability has been resolved:

iommu/sva: Fix crash in iommu_sva_unbind_device()

domain->mm->iommu_mm can be freed by iommu_domain_free():
  iommu_domain_free()
    mmdrop()
      __mmdrop()
        mm_pasid_drop()
After iommu_domain_free() returns, accessing domain->mm->iommu_mm may
dereference a freed mm structure, leading to a crash.

Fix this by moving the code that accesses domain->mm->iommu_mm to before
the call to iommu_domain_free().