Re: [Patch net] net_sched: fix a missing rcu barrier in mini_qdisc_pair_swap()
flat view
From: Jiri Pirko <jiri@resnulli.us>
Date: 2017-12-22 10:24:26
Thu, Dec 21, 2017 at 08:26:24AM CET, xiyou.wangcong@gmail.com wrote:
The rcu_barrier_bh() in mini_qdisc_pair_swap() is to wait for
flying RCU callback installed by a previous mini_qdisc_pair_swap(),
however we miss it on the tp_head==NULL path, which leads to that
the RCU callback still uses miniq_old->rcu after it is freed together
with qdisc in qdisc_graft(). So just add it on that path too.
Fixes: 46209401f8f6 ("net: core: introduce mini_Qdisc and eliminate usage of tp->q for clsact fastpath ")
Reported-by: Jakub Kicinski <redacted>
Tested-by: Jakub Kicinski <redacted>
Cc: Jiri Pirko <redacted>
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <redacted>Acked-by: Jiri Pirko <redacted>