From 22f7cec93f0af86c4b66bf34a977da9d7cef076e Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 6 Nov 2017 13:47:23 -0800 Subject: cls_flow: 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_flow.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'net') diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c index 67f3a2af6aab..85f765cff697 100644 --- a/net/sched/cls_flow.c +++ b/net/sched/cls_flow.c @@ -372,15 +372,21 @@ static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = { [TCA_FLOW_PERTURB] = { .type = NLA_U32 }, }; -static void flow_destroy_filter_work(struct work_struct *work) +static void __flow_destroy_filter(struct flow_filter *f) { - struct flow_filter *f = container_of(work, struct flow_filter, work); - - rtnl_lock(); del_timer_sync(&f->perturb_timer); tcf_exts_destroy(&f->exts); tcf_em_tree_destroy(&f->ematches); + tcf_exts_put_net(&f->exts); kfree(f); +} + +static void flow_destroy_filter_work(struct work_struct *work) +{ + struct flow_filter *f = container_of(work, struct flow_filter, work); + + rtnl_lock(); + __flow_destroy_filter(f); rtnl_unlock(); } @@ -552,8 +558,10 @@ static int flow_change(struct net *net, struct sk_buff *in_skb, *arg = fnew; - if (fold) + if (fold) { + tcf_exts_get_net(&fold->exts); call_rcu(&fold->rcu, flow_destroy_filter); + } return 0; err2: @@ -570,6 +578,7 @@ static int flow_delete(struct tcf_proto *tp, void *arg, bool *last) struct flow_filter *f = arg; list_del_rcu(&f->list); + tcf_exts_get_net(&f->exts); call_rcu(&f->rcu, flow_destroy_filter); *last = list_empty(&head->filters); return 0; @@ -594,7 +603,10 @@ static void flow_destroy(struct tcf_proto *tp) list_for_each_entry_safe(f, next, &head->filters, list) { list_del_rcu(&f->list); - call_rcu(&f->rcu, flow_destroy_filter); + if (tcf_exts_get_net(&f->exts)) + call_rcu(&f->rcu, flow_destroy_filter); + else + __flow_destroy_filter(f); } kfree_rcu(head, rcu); } -- cgit v1.2.3