[PATCH] ACPICA: DEBUGGER: Add return value check to acpi_db_walk_for_fields()

[shenzijun]

From: Zijun Shen <shenzijun@xxxxxxxxxx>

The function acpi_db_walk_for_fields frees buffer.pointer by the
first ACPI_FREE. And then uses the second ACPI_FREE to free
buffer.pointer which may assigns again in acpi_evaluate_object.
It's necessary to make sure that buffer.pointer get a block of
memory in acpi_evaluate_object and acpi_evaluate_object return 0.

Signed-off-by: Zijun Shen <shenzijun@xxxxxxxxxx>
---
 drivers/acpi/acpica/dbnames.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/acpica/dbnames.c b/drivers/acpi/acpica/dbnames.c
index 3615e1a6efd8..7a2d980cb2b8 100644
--- a/drivers/acpi/acpica/dbnames.c
+++ b/drivers/acpi/acpica/dbnames.c
@@ -550,7 +550,10 @@ acpi_db_walk_for_fields(acpi_handle obj_handle,
 	ACPI_FREE(buffer.pointer);
 
 	buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
-	acpi_evaluate_object(obj_handle, NULL, NULL, &buffer);
+	status = acpi_evaluate_object(obj_handle, NULL, NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		return (AE_OK);
+	}
 
 	/*
 	 * Since this is a field unit, surround the output in braces
-- 
2.31.1