Describe CVE-2021-47467.
What is CVE-2021-47467?
In the Linux kernel, the following vulnerability has been resolved:

kunit: fix reference count leak in kfree_at_end

The reference counting issue happens in the normal path of
kfree_at_end(). When kunit_alloc_and_get_resource() is invoked, the
function forgets to handle the returned resource object, whose refcount
increased inside, causing a refcount leak.

Fix this issue by calling kunit_alloc_resource() instead of
kunit_alloc_and_get_resource().

Fixed the following when applying:
Shuah Khan <skhan@linuxfoundation.org>

CHECK: Alignment should match open parenthesis
+	kunit_alloc_resource(test, NULL, kfree_res_free, GFP_KERNEL,
 				     (void *)to_free);.