On Thu, Jun 1, 2017 at 9:21 AM, Paolo Abeni [off-list ref] wrote:

I'm sorry, I do not follow. I'm concerned about the secpath field (skb-

quoted

sp), which is the only one that can be not NULL in

__udp_queue_rcv_skb().

If the secpath is not NULL, calling there secpath_reset() (or the to-
be-introduced skb_reset_head_state()), we will properly release it and
we will clear the field, too.

Calling skb_release_head_state() in the same scenario, we release the
secpath, but we don't clear it. So if the packet is later dropped we
will get a double free, unless we add and use a specialized a
free_stateless_skb(), too.

Then simply use secpath_reset() instead of secpath_put() from
skb_release_head_state()

Clearly having these subtle differences bring confusion, for very little gain.

secpath_put() should be removed. Most of its callers simply set
skb->sp back to NULL anyway.