From c2f3f31d402be4849b06282c3a5278f2865c9fcc Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 26 Oct 2017 18:24:37 -0700 Subject: net_sched: use tcf_queue_work() in route 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_route.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'net/sched/cls_route.c') diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c index 9ddde65915d2..4b14ccd8b8f2 100644 --- a/net/sched/cls_route.c +++ b/net/sched/cls_route.c @@ -57,7 +57,10 @@ struct route4_filter { u32 handle; struct route4_bucket *bkt; struct tcf_proto *tp; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; #define ROUTE4_FAILURE ((struct route4_filter *)(-1L)) @@ -254,12 +257,22 @@ static int route4_init(struct tcf_proto *tp) return 0; } -static void route4_delete_filter(struct rcu_head *head) +static void route4_delete_filter_work(struct work_struct *work) { - struct route4_filter *f = container_of(head, struct route4_filter, rcu); + struct route4_filter *f = container_of(work, struct route4_filter, work); + rtnl_lock(); tcf_exts_destroy(&f->exts); kfree(f); + rtnl_unlock(); +} + +static void route4_delete_filter(struct rcu_head *head) +{ + struct route4_filter *f = container_of(head, struct route4_filter, rcu); + + INIT_WORK(&f->work, route4_delete_filter_work); + tcf_queue_work(&f->work); } static void route4_destroy(struct tcf_proto *tp) -- cgit v1.2.3-70-g09d2 From 3fd51de5e3ba447624a08a8ba29f90d94f0fe909 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 6 Nov 2017 13:47:27 -0800 Subject: cls_route: 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_route.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'net/sched/cls_route.c') diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c index 4b14ccd8b8f2..ac9a5b8825b9 100644 --- a/net/sched/cls_route.c +++ b/net/sched/cls_route.c @@ -257,13 +257,19 @@ static int route4_init(struct tcf_proto *tp) return 0; } +static void __route4_delete_filter(struct route4_filter *f) +{ + tcf_exts_destroy(&f->exts); + tcf_exts_put_net(&f->exts); + kfree(f); +} + static void route4_delete_filter_work(struct work_struct *work) { struct route4_filter *f = container_of(work, struct route4_filter, work); rtnl_lock(); - tcf_exts_destroy(&f->exts); - kfree(f); + __route4_delete_filter(f); rtnl_unlock(); } @@ -297,7 +303,10 @@ static void route4_destroy(struct tcf_proto *tp) next = rtnl_dereference(f->next); RCU_INIT_POINTER(b->ht[h2], next); tcf_unbind_filter(tp, &f->res); - call_rcu(&f->rcu, route4_delete_filter); + if (tcf_exts_get_net(&f->exts)) + call_rcu(&f->rcu, route4_delete_filter); + else + __route4_delete_filter(f); } } RCU_INIT_POINTER(head->table[h1], NULL); @@ -338,6 +347,7 @@ static int route4_delete(struct tcf_proto *tp, void *arg, bool *last) /* Delete it */ tcf_unbind_filter(tp, &f->res); + tcf_exts_get_net(&f->exts); call_rcu(&f->rcu, route4_delete_filter); /* Strip RTNL protected tree */ @@ -541,6 +551,7 @@ static int route4_change(struct net *net, struct sk_buff *in_skb, *arg = f; if (fold) { tcf_unbind_filter(tp, &fold->res); + tcf_exts_get_net(&fold->exts); call_rcu(&fold->rcu, route4_delete_filter); } return 0; -- cgit v1.2.3-70-g09d2