batman-adv: tt: transition NEW local entries only under lock

The batadv_tt_local_size_inc() must never be called for an entry which was
already removed from the list. Otherwise the removal from the hash cannot
correctly determine if the batadv_tt_local_size_dec() needs to be called or
not.

This assumption is broken by the use of rcu_read_lock() in
batadv_tt_local_transition_new() because it might still see entries in the
list which were already removed by a different context from the list. If it
then increments the size counter, nothing will reduce the counter again.
Simply because the removal (responsible for the decrement) already
happened.

Over the whole time, the actual hash list spinlock must be held when
transitioning NEW local entries to avoid list manipulations.

Signed-off-by: Sven Eckelmann <sven@narfation.org>

0 files changed, 0 insertions, 0 deletions