From d5f984f5af1d926bc9c7a7f90e7a1e1e313a8ba7 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 6 Nov 2017 13:47:25 -0800 Subject: [PATCH] cls_fw: 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_fw.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c index 99183b8621ec..7f45e5ab8afc 100644 --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -122,13 +122,19 @@ static int fw_init(struct tcf_proto *tp) return 0; } +static void __fw_delete_filter(struct fw_filter *f) +{ + tcf_exts_destroy(&f->exts); + tcf_exts_put_net(&f->exts); + kfree(f); +} + static void fw_delete_filter_work(struct work_struct *work) { struct fw_filter *f = container_of(work, struct fw_filter, work); rtnl_lock(); - tcf_exts_destroy(&f->exts); - kfree(f); + __fw_delete_filter(f); rtnl_unlock(); } @@ -154,7 +160,10 @@ static void fw_destroy(struct tcf_proto *tp) RCU_INIT_POINTER(head->ht[h], rtnl_dereference(f->next)); tcf_unbind_filter(tp, &f->res); - call_rcu(&f->rcu, fw_delete_filter); + if (tcf_exts_get_net(&f->exts)) + call_rcu(&f->rcu, fw_delete_filter); + else + __fw_delete_filter(f); } } kfree_rcu(head, rcu); @@ -179,6 +188,7 @@ static int fw_delete(struct tcf_proto *tp, void *arg, bool *last) if (pfp == f) { RCU_INIT_POINTER(*fp, rtnl_dereference(f->next)); tcf_unbind_filter(tp, &f->res); + tcf_exts_get_net(&f->exts); call_rcu(&f->rcu, fw_delete_filter); ret = 0; break; @@ -299,6 +309,7 @@ static int fw_change(struct net *net, struct sk_buff *in_skb, RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next)); rcu_assign_pointer(*fp, fnew); tcf_unbind_filter(tp, &f->res); + tcf_exts_get_net(&f->exts); call_rcu(&f->rcu, fw_delete_filter); *arg = fnew;