packet: fix races in fanout_add()
Multiple threads can call fanout_add() at the same time.
We need to grab fanout_mutex earlier to avoid races that could
lead to one thread freeing po->rollover that was set by another thread.
Do the same in fanout_release(), for peace of mind, and to help us
finding lockdep issues earlier.
Change-Id: Ie7e3cf22d10779f6d00f1054afb2dcfac6870660
Fixes: dc99f600698d ("packet: Add fanout support.")
Fixes: 0648ab70afe6 ("packet: rollover prepare: per-socket state")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed