On Thu, 2017-06-01 at 22:35 +0200, Paolo Abeni wrote:

To make the code robust we would have to NULL all the other fields
(nfct, nf_bridge, destructor, sk) that are currently not cleared in
skb_release_head_state(), elsewhere if one day, after some change, any
that fields become non-NULL in this code path we risk a double-free
after skb_release_head_state(), even if the code looks safe.

Well, one can not predict future bugs, and we should not add code just
trying to prevent future bugs.

Will that be a little too invasive for this small use-case? Can't we
prefer a new helper or simply a secpath_reset() plus some appropriate
comments?

Please reuse existing functions, and amend them if needed.

Fact that we mention secpath_put() or secpath_reset() in an UDP patch
should really tell us something is wrong. This is becoming a maintenance
burden.