[PATCH 3.8 03/91] ACPICA: Return error if DerefOf resolves to a null package element.

From: Kamal Mostafa
Date: Thu Nov 07 2013 - 21:41:20 EST


3.8.13.13 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Bob Moore <robert.moore@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/acpi/acpica/exoparg1.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/acpica/exoparg1.c b/drivers/acpi/acpica/exoparg1.c
index 1fa1ad6..c9f1a21 100644
--- a/drivers/acpi/acpica/exoparg1.c
+++ b/drivers/acpi/acpica/exoparg1.c
@@ -969,10 +969,17 @@ acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)
*/
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;

default:
--
1.8.1.2

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