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From:   Daniil Tatianin <d-tatianin@yandex-team.ru>
To:     Robert Moore <robert.moore@intel.com>
Cc:     Daniil Tatianin <d-tatianin@yandex-team.ru>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Len Brown <lenb@kernel.org>, linux-acpi@vger.kernel.org,
        devel@acpica.org, linux-kernel@vger.kernel.org
Subject: [PATCH v0] ACPICA: nsrepair: handle cases without a return value correctly
Date:   Sat,  7 Jan 2023 02:53:08 +0300
Message-Id: <20230106235308.99999-1-d-tatianin@yandex-team.ru>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Previously acpi_ns_simple_repair() would crash if expected_btypes
contained any combination of ACPI_RTYPE_NONE with a different type,
e.g | ACPI_RTYPE_INTEGER because of slightly incorrect logic in the
!return_object branch, which wouldn't return AE_AML_NO_RETURN_VALUE
for such cases.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Link: https://github.com/acpica/acpica/pull/811
Fixes: 61db45ca2163 ("ACPICA: Restore code that repairs NULL package elements in return values.")
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
 drivers/acpi/acpica/nsrepair.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/acpica/nsrepair.c b/drivers/acpi/acpica/nsrepair.c
index 367fcd201f96..ec512e06a48e 100644
--- a/drivers/acpi/acpica/nsrepair.c
+++ b/drivers/acpi/acpica/nsrepair.c
@@ -181,8 +181,9 @@ acpi_ns_simple_repair(struct acpi_evaluate_info *info,
 	 * Try to fix if there was no return object. Warning if failed to fix.
 	 */
 	if (!return_object) {
-		if (expected_btypes && (!(expected_btypes & ACPI_RTYPE_NONE))) {
-			if (package_index != ACPI_NOT_PACKAGE_ELEMENT) {
+		if (expected_btypes) {
+			if (!(expected_btypes & ACPI_RTYPE_NONE) &&
+			    package_index != ACPI_NOT_PACKAGE_ELEMENT) {
 				ACPI_WARN_PREDEFINED((AE_INFO,
 						      info->full_pathname,
 						      ACPI_WARN_ALWAYS,
@@ -196,14 +197,15 @@ acpi_ns_simple_repair(struct acpi_evaluate_info *info,
 				if (ACPI_SUCCESS(status)) {
 					return (AE_OK);	/* Repair was successful */
 				}
-			} else {
+			}
+
+			if (expected_btypes != ACPI_RTYPE_NONE) {
 				ACPI_WARN_PREDEFINED((AE_INFO,
 						      info->full_pathname,
 						      ACPI_WARN_ALWAYS,
 						      "Missing expected return value"));
+				return (AE_AML_NO_RETURN_VALUE);
 			}
-
-			return (AE_AML_NO_RETURN_VALUE);
 		}
 	}
 
-- 
2.25.1