[PATCH] ACPICA: add more parameter validation for acpi_walk_namespace()

[Cryolitia PukNgae via B4 Relay]

From: Cryolitia PukNgae <cryolitia@xxxxxxxxxxxxx>

On the Honor FMB-P-PCB laptop, an incorrect ACPI table causes
sdw_intel_acpi_scan to pass a NULL pointer as start_object to
acpi_walk_namespace() when calling it, which eventually causes the
kernel to report a NULL pointer dereference[1].

1. https://gist.github.com/Cryolitia/a860ffc97437dcd2cd988371d5b73ed7

Signed-off-by: Cryolitia PukNgae <cryolitia@xxxxxxxxxxxxx>
---
 drivers/acpi/acpica/nsxfeval.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c
index f9d059647cc52e94ce013af3382addba338820e8..c1f318ea7d5fcd846dc158b155286a6f5bba4cff 100644
--- a/drivers/acpi/acpica/nsxfeval.c
+++ b/drivers/acpi/acpica/nsxfeval.c
@@ -564,7 +564,7 @@ acpi_walk_namespace(acpi_object_type type,
 
 	/* Parameter validation */
 
-	if ((type > ACPI_TYPE_LOCAL_MAX) ||
+	if ((type > ACPI_TYPE_LOCAL_MAX) || (start_object == NULL) ||
 	    (!max_depth) || (!descending_callback && !ascending_callback)) {
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}

---
base-commit: 24ea63ea387714634813359e2c8e0e6c36952f73
change-id: 20250815-acpi_fix-3724e6c4da02

Best regards,
-- 
Cryolitia PukNgae <cryolitia@xxxxxxxxxxxxx>