From b1b5b04fdb6da262aef37ef83b9f2e41326720ef Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 26 Oct 2017 18:24:31 -0700 Subject: net_sched: use tcf_queue_work() in cgroup filter Defer the tcf_exts_destroy() in RCU callback to tc filter workqueue and get RTNL lock. Reported-by: Chris Mi Cc: Daniel Borkmann Cc: Jiri Pirko Cc: John Fastabend Cc: Jamal Hadi Salim Cc: "Paul E. McKenney" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_cgroup.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'net/sched/cls_cgroup.c') diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index d48452f87975..a97e069bee89 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -23,7 +23,10 @@ struct cls_cgroup_head { struct tcf_exts exts; struct tcf_ematch_tree ematches; struct tcf_proto *tp; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, @@ -57,15 +60,26 @@ static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, }; +static void cls_cgroup_destroy_work(struct work_struct *work) +{ + struct cls_cgroup_head *head = container_of(work, + struct cls_cgroup_head, + work); + rtnl_lock(); + tcf_exts_destroy(&head->exts); + tcf_em_tree_destroy(&head->ematches); + kfree(head); + rtnl_unlock(); +} + static void cls_cgroup_destroy_rcu(struct rcu_head *root) { struct cls_cgroup_head *head = container_of(root, struct cls_cgroup_head, rcu); - tcf_exts_destroy(&head->exts); - tcf_em_tree_destroy(&head->ematches); - kfree(head); + INIT_WORK(&head->work, cls_cgroup_destroy_work); + tcf_queue_work(&head->work); } static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, -- cgit v1.2.3-59-g8ed1b