iommu/amd: Fix NULL dereference bug in match_hid_uid
Add a non-NULL check to fix potential NULL pointer dereference
Cleanup code to call function once.
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Fixes: 2bf9a0a12749b ('iommu/amd: Add iommu support for ACPI HID devices')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 6b0760d..b319e51 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -140,10 +140,14 @@
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;
