From 0b2a59894b7657fab46b50f176bd772aa495044f Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 6 Nov 2017 13:47:20 -0800 Subject: [PATCH] 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(-) 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); -- 2.20.1