[PATCH 4.14 069/315] ACPICA: Fix memory leak caused by _CID repair function

[Greg Kroah-Hartman]

From: Erik Kaneda <erik.kaneda@xxxxxxxxx>

[ Upstream commit c27bac0314131b11bccd735f7e8415ac6444b667 ]

ACPICA commit 180cb53963aa876c782a6f52cc155d951b26051a

According to the ACPI spec, _CID returns a package containing
hardware ID's. Each element of an ASL package contains a reference
count from the parent package as well as the element itself.

Name (TEST, Package() {
    "String object" // this package element has a reference count of 2
})

A memory leak was caused in the _CID repair function because it did
not decrement the reference count created by the package. Fix the
memory leak by calling acpi_ut_remove_reference on _CID package elements
that represent a hardware ID (_HID).

Link: https://github.com/acpica/acpica/commit/180cb539
Tested-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
Signed-off-by: Erik Kaneda <erik.kaneda@xxxxxxxxx>
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/acpi/acpica/nsrepair2.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/acpi/acpica/nsrepair2.c b/drivers/acpi/acpica/nsrepair2.c
index 06037e044694..78b802b5f7d3 100644
--- a/drivers/acpi/acpica/nsrepair2.c
+++ b/drivers/acpi/acpica/nsrepair2.c
@@ -409,6 +409,13 @@ acpi_ns_repair_CID(struct acpi_evaluate_info *info,
 
 			(*element_ptr)->common.reference_count =
 			    original_ref_count;
+
+			/*
+			 * The original_element holds a reference from the package object
+			 * that represents _HID. Since a new element was created by _HID,
+			 * remove the reference from the _CID package.
+			 */
+			acpi_ut_remove_reference(original_element);
 		}
 
 		element_ptr++;
-- 
2.30.2