From: Aaron Ma <aaron.ma@xxxxxxxxxxxxx> [ Upstream commit bb6bccba390c7d743c1e4427de4ef284c8cc6869 ] Add a non-NULL check to fix potential NULL pointer dereference Cleanup code to call function once. Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx> Fixes: 2bf9a0a12749b ('iommu/amd: Add iommu support for ACPI HID devices') Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/amd_iommu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 1f2ed44de2438..fe18804a50083 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -139,10 +139,14 @@ 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; -- 2.20.1