act_mirred: fix a race condition on mirred_list

After commit 1ce87720d456 ("net: sched: make cls_u32 lockless")
we began to release tc actions in a RCU callback. However,
mirred action relies on RTNL lock to protect the global
mirred_list, therefore we could have a race condition
between RCU callback and netdevice event, which caused
a list corruption as reported by Vinson.

Instead of relying on RTNL lock, introduce a spinlock to
protect this list.

Note, in non-bind case, it is still called with RTNL lock,
therefore should disable BH too.

Reported-by: Vinson Lee <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: Jamal Hadi Salim <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Acked-by: Jamal Hadi Salim <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions