From 55334a5db5cd32b207ac697cec3ec8e078f345d4 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Tue, 11 Feb 2014 17:07:34 -0800 Subject: [PATCH] net_sched: act: refuse to remove bound action outside When an action is bonnd to a filter, there is no point to remove it outside. Currently we just silently decrease the refcnt, we should reject this explicitly with EPERM. Cc: Jamal Hadi Salim Cc: David S. Miller Signed-off-by: Cong Wang Signed-off-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- include/net/act_api.h | 2 +- net/sched/act_api.c | 26 ++++++++++++++++++++------ 2 files changed, 21 insertions(+), 7 deletions(-) diff --git a/include/net/act_api.h b/include/net/act_api.h index 969cac6344aa..3ee4c92afd1b 100644 --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -109,7 +109,7 @@ void tcf_hash_insert(struct tc_action *a); int tcf_register_action(struct tc_action_ops *a, unsigned int mask); int tcf_unregister_action(struct tc_action_ops *a); -void tcf_action_destroy(struct list_head *actions, int bind); +int tcf_action_destroy(struct list_head *actions, int bind); int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions, struct tcf_result *res); int tcf_action_init(struct net *net, struct nlattr *nla, diff --git a/net/sched/act_api.c b/net/sched/act_api.c index c88d382d3b09..27e4c531ade1 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -53,6 +53,8 @@ int tcf_hash_release(struct tc_action *a, int bind) if (p) { if (bind) p->tcfc_bindcnt--; + else if (p->tcfc_bindcnt > 0) + return -EPERM; p->tcfc_refcnt--; if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) { @@ -123,6 +125,7 @@ static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a) struct tcf_common *p; struct nlattr *nest; int i = 0, n_i = 0; + int ret = -EINVAL; nest = nla_nest_start(skb, a->order); if (nest == NULL) @@ -133,10 +136,12 @@ static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a) head = &hinfo->htab[tcf_hash(i, hinfo->hmask)]; hlist_for_each_entry_safe(p, n, head, tcfc_head) { a->priv = p; - if (ACT_P_DELETED == tcf_hash_release(a, 0)) { + ret = tcf_hash_release(a, 0); + if (ret == ACT_P_DELETED) { module_put(a->ops->owner); n_i++; - } + } else if (ret < 0) + goto nla_put_failure; } } if (nla_put_u32(skb, TCA_FCNT, n_i)) @@ -146,7 +151,7 @@ static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a) return n_i; nla_put_failure: nla_nest_cancel(skb, nest); - return -EINVAL; + return ret; } static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb, @@ -401,16 +406,21 @@ exec_done: } EXPORT_SYMBOL(tcf_action_exec); -void tcf_action_destroy(struct list_head *actions, int bind) +int tcf_action_destroy(struct list_head *actions, int bind) { struct tc_action *a, *tmp; + int ret = 0; list_for_each_entry_safe(a, tmp, actions, list) { - if (tcf_hash_release(a, bind) == ACT_P_DELETED) + ret = tcf_hash_release(a, bind); + if (ret == ACT_P_DELETED) module_put(a->ops->owner); + else if (ret < 0) + return ret; list_del(&a->list); kfree(a); } + return ret; } int @@ -838,7 +848,11 @@ tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions, } /* now do the delete */ - tcf_action_destroy(actions, 0); + ret = tcf_action_destroy(actions, 0); + if (ret < 0) { + kfree_skb(skb); + return ret; + } ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC, n->nlmsg_flags & NLM_F_ECHO); -- 2.30.2