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

commit c0df975f9045d6b2b13d88746e628ac308ff49ea upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 9a4f05e5b23fa480e308d0b44373e6599ad82982..55f1515d54c9d7055731dc660be23491da3e21e9 100644 (file)
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -677,8 +677,7 @@ static int __init dmar_acpi_dev_scope_init(void)
                                       andd->object_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->object_name);
                                continue;