Merge pull request #850 from tamird/ub-member-access-within-misaligned-address-two

Avoid undefined behavior: member access within misaligned address

1 files changed, 8 insertions, 3 deletions

diff --git a/source/components/utilities/utresrc.c b/source/components/utilities/utresrc.c
index 7898e9929..f47b29246 100644
--- a/source/components/utilities/utresrc.c
+++ b/source/components/utilities/utresrc.c
@@ -532,16 +532,21 @@ AcpiUtValidateResource (
     AmlResource = ACPI_CAST_PTR (AML_RESOURCE, Aml);
     if (ResourceType == ACPI_RESOURCE_NAME_SERIAL_BUS)
     {
+        /* Avoid undefined behavior: member access within misaligned address */
+
+        AML_RESOURCE_COMMON_SERIALBUS CommonSerialBus;
+        memcpy(&CommonSerialBus, AmlResource, sizeof(CommonSerialBus));
+
         /* Validate the BusType field */
 
-        if ((AmlResource->CommonSerialBus.Type == 0) ||
-            (AmlResource->CommonSerialBus.Type > AML_RESOURCE_MAX_SERIALBUSTYPE))
+        if ((CommonSerialBus.Type == 0) ||
+            (CommonSerialBus.Type > AML_RESOURCE_MAX_SERIALBUSTYPE))
         {
             if (WalkState)
             {
                 ACPI_ERROR ((AE_INFO,
                     "Invalid/unsupported SerialBus resource descriptor: BusType 0x%2.2X",
-                    AmlResource->CommonSerialBus.Type));
+                    CommonSerialBus.Type));
             }
             return (AE_AML_INVALID_RESOURCE_TYPE);
         }