From bb6bccba390c7d743c1e4427de4ef284c8cc6869 Mon Sep 17 00:00:00 2001 From: Aaron Ma Date: Wed, 13 Mar 2019 21:53:24 +0800 Subject: 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 Fixes: 2bf9a0a12749b ('iommu/amd: Add iommu support for ACPI HID devices') Signed-off-by: Joerg Roedel --- 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 6b0760dafb3e..b319e51c379b 100644 --- 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; -- cgit v1.2.3-55-g7522