Merge tag 'iommu-fix-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...

Pull IOMMU fix from Joerg Roedel:
 "Fix a NULL-pointer dereference issue in the ACPI device matching code
  of the AMD IOMMU driver"

* tag 'iommu-fix-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix NULL dereference bug in match_hid_uid

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 6b0760d..b319e51 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -140,10 +140,14 @@ static struct lock_class_key reserved_rbtree_key;
 static inline int match_hid_uid(struct device *dev,
                                struct acpihid_map_entry *entry)
 {
+       struct acpi_device *adev = ACPI_COMPANION(dev);
        const char *hid, *uid;
 
-       hid = acpi_device_hid(ACPI_COMPANION(dev));
-       uid = acpi_device_uid(ACPI_COMPANION(dev));
+       if (!adev)
+               return -ENODEV;
+
+       hid = acpi_device_hid(adev);
+       uid = acpi_device_uid(adev);
 
        if (!hid || !(*hid))
                return -ENODEV;