iommu/vt-d: Check return value of acpi_bus_get_device()

Checking adev == NULL is not sufficient as
acpi_bus_get_device() might not touch the value of this
parameter in an error case, so check the return value
directly.

Fixes: ed40356b5fcf1ce28e026ab39c5b2b6939068b50
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 60ab474bfff3..06d268abe951 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -678,8 +678,7 @@ static int __init dmar_acpi_dev_scope_init(void)
                                        andd->device_name);
                                 continue;
                         }
-                        acpi_bus_get_device(h, &adev);
-                        if (!adev) {
+                        if (acpi_bus_get_device(h, &adev)) {
                                 pr_err("Failed to get device for ACPI object %s\n",
                                        andd->device_name);
                                 continue;