[PATCH 4.19 087/421] ACPICA: Fix memory leak caused by _CID repair function

Greg Kroah-Hartman
2021-07-19T16:07:56Z

From: Erik Kaneda <erik.kaneda@intel.com>

[ 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@linaro.org>
Signed-off-by: Erik Kaneda <erik.kaneda@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 a3bd6280882c..4c8ce483805d 100644
--- a/drivers/acpi/acpica/nsrepair2.c
+++ b/drivers/acpi/acpica/nsrepair2.c
@@ -375,6 +375,13 @@ 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