From c96a48385d53089ee9977dd0bce82a9493984484 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 26 Oct 2017 18:24:29 -0700 Subject: net_sched: use tcf_queue_work() in basic 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_basic.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'net/sched/cls_basic.c') diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c index d89ebafd2239..f177649a2419 100644 --- a/net/sched/cls_basic.c +++ b/net/sched/cls_basic.c @@ -34,7 +34,10 @@ struct basic_filter { struct tcf_result res; struct tcf_proto *tp; struct list_head link; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, @@ -82,15 +85,26 @@ static int basic_init(struct tcf_proto *tp) return 0; } -static void basic_delete_filter(struct rcu_head *head) +static void basic_delete_filter_work(struct work_struct *work) { - struct basic_filter *f = container_of(head, struct basic_filter, rcu); + struct basic_filter *f = container_of(work, struct basic_filter, work); + rtnl_lock(); tcf_exts_destroy(&f->exts); tcf_em_tree_destroy(&f->ematches); + rtnl_unlock(); + kfree(f); } +static void basic_delete_filter(struct rcu_head *head) +{ + struct basic_filter *f = container_of(head, struct basic_filter, rcu); + + INIT_WORK(&f->work, basic_delete_filter_work); + tcf_queue_work(&f->work); +} + static void basic_destroy(struct tcf_proto *tp) { struct basic_head *head = rtnl_dereference(tp->root); -- cgit From 0b2a59894b7657fab46b50f176bd772aa495044f Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 6 Nov 2017 13:47:20 -0800 Subject: cls_basic: use tcf_exts_get_net() before call_rcu() Hold netns refcnt before call_rcu() and release it after the tcf_exts_destroy() is done. Note, on ->destroy() path we have to respect the return value of tcf_exts_get_net(), on other paths it should always return true, so we don't need to care. Cc: Lucas Bates Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_basic.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'net/sched/cls_basic.c') diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c index f177649a2419..e43c56d5b96a 100644 --- a/net/sched/cls_basic.c +++ b/net/sched/cls_basic.c @@ -85,16 +85,21 @@ static int basic_init(struct tcf_proto *tp) return 0; } +static void __basic_delete_filter(struct basic_filter *f) +{ + tcf_exts_destroy(&f->exts); + tcf_em_tree_destroy(&f->ematches); + tcf_exts_put_net(&f->exts); + kfree(f); +} + static void basic_delete_filter_work(struct work_struct *work) { struct basic_filter *f = container_of(work, struct basic_filter, work); rtnl_lock(); - tcf_exts_destroy(&f->exts); - tcf_em_tree_destroy(&f->ematches); + __basic_delete_filter(f); rtnl_unlock(); - - kfree(f); } static void basic_delete_filter(struct rcu_head *head) @@ -113,7 +118,10 @@ static void basic_destroy(struct tcf_proto *tp) list_for_each_entry_safe(f, n, &head->flist, link) { list_del_rcu(&f->link); tcf_unbind_filter(tp, &f->res); - call_rcu(&f->rcu, basic_delete_filter); + if (tcf_exts_get_net(&f->exts)) + call_rcu(&f->rcu, basic_delete_filter); + else + __basic_delete_filter(f); } kfree_rcu(head, rcu); } @@ -125,6 +133,7 @@ static int basic_delete(struct tcf_proto *tp, void *arg, bool *last) list_del_rcu(&f->link); tcf_unbind_filter(tp, &f->res); + tcf_exts_get_net(&f->exts); call_rcu(&f->rcu, basic_delete_filter); *last = list_empty(&head->flist); return 0; @@ -219,6 +228,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb, if (fold) { list_replace_rcu(&fold->link, &fnew->link); tcf_unbind_filter(tp, &fold->res); + tcf_exts_get_net(&fold->exts); call_rcu(&fold->rcu, basic_delete_filter); } else { list_add_rcu(&fnew->link, &head->flist); -- cgit