[PATCH 3.11 04/36] ACPICA: Return error if DerefOf resolves to a null package element.

Greg Kroah-Hartman
2013-11-26T18:13:05Z

From: Bob Moore <robert.moore@intel.com>

commit a50abf4842dd7d603a2ad6dcc7f1467fd2a66f03 upstream.

Disallow the dereference of a reference (via index) to an uninitialized
package element. Provides compatibility with other ACPI
implementations. ACPICA BZ 1003.

References: https://bugs.acpica.org/show_bug.cgi?id=431
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/acpi/acpica/exoparg1.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/acpi/acpica/exoparg1.c
+++ b/drivers/acpi/acpica/exoparg1.c
@@ -962,10 +962,17 @@ acpi_status acpi_ex_opcode_1A_0T_1R(stru
*/
return_desc =
*(operand[0]->reference.where);
- if (return_desc) {
- acpi_ut_add_reference
- (return_desc);
+ if (!return_desc) {
+ /*
+ * Element is NULL, do not allow the dereference.
+ * This provides compatibility with other ACPI
+ * implementations.
+ */
+ return_ACPI_STATUS
+ (AE_AML_UNINITIALIZED_ELEMENT);
}
+
+ acpi_ut_add_reference(return_desc);
break;