[PATCH v1] ACPI: utils: Fix error path in acpi_evaluate_reference()

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

If a pointer to an uninitialized struct acpi_handle_list is passed to
acpi_evaluate_reference() and it decides to bail out early, either
because acpi_evaluate_object() fails, or because it produces invalid
data, the handles pointer from the struct acpi_handle_list will be
passed to kfree() and if it is not NULL, the kernel will crash.

Address this by moving the "end" label in acpi_evaluate_reference() to
the end of the function, which is sufficient, because no cleanup is
needed in that case.

Fixes: 2e57d10a6591 ("ACPI: utils: Dynamically determine acpi_handle_list size")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/utils.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-pm/drivers/acpi/utils.c
===================================================================
--- linux-pm.orig/drivers/acpi/utils.c
+++ linux-pm/drivers/acpi/utils.c
@@ -399,13 +399,13 @@ acpi_evaluate_reference(acpi_handle hand
 		acpi_handle_debug(list->handles[i], "Found in reference list\n");
 	}
 
-end:
 	if (ACPI_FAILURE(status)) {
 		list->count = 0;
 		kfree(list->handles);
 		list->handles = NULL;
 	}
 
+end:
 	kfree(buffer.pointer);
 
 	return status;