Commit 84751b98c1 ('WPS: Allow wildcard
UUID PIN to be used twice') relaxed the constraints on how many time a
wildcard PIN can be used to allow two attempts. However, it did this in
a way that could result in concurrent attempts resulting in the wildcard
PIN being invalidated even without the second attempt actually going as
far as trying to use the PIN and a WPS protocol run.
wildcard_uuid is a flag/counter set for wildcard PINs and it is
incremented whenever the PIN is retrieved by wps_registrar_get_pin().
Eventually it causes the wildcard PIN to be released, effectively
limiting the number of registration attempts with a wildcard PIN.
With the previous implementation, when the PIN is in use and locked
(PIN_LOCKED), it is not returned from wps_registrar_get_pin() but
wildcard_uuid is still incremented which can cause the PIN to be
released earlier and stations will have fewer registration attempts with
it. Fix this scenario by only incrementing wildcard_uuid if the PIN is
actually going to be returned and used.
Signed-off-by: Lior David <qca_liord@qca.qualcomm.com>