From: Patrick McHardy <redacted>
Date: Thu, 27 Nov 2008 13:57:19 +0100

commit 57b0afc97f8249f0b4f665aa285ed89a9178ba42
Author: Patrick McHardy [off-list ref]
Date:   Thu Nov 27 13:40:31 2008 +0100

    netlink: allow empty nested attributes
    
    validate_nla() currently doesn't allow empty nested attributes. This
    makes userspace code unnecessarily complicated when starting and ending
    the nested attribute is done by generic upper level code and the inner
    attributes are dumped by a module.
    
    Add a special case to accept empty nested attributes. When the nested
    attribute is non empty, the same checks as before are performed.
    
    Signed-off-by: Patrick McHardy [off-list ref]

Applied, thanks Patrick.