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Commit 033b228e authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

net_sched: fix a memory leak in cls_tcindex 



When tcindex_destroy() destroys all the filter results in
the perfect hash table, it invokes the walker to delete
each of them. However, results with class==0 are skipped
in either tcindex_walk() or tcindex_delete(), which causes
a memory leak reported by kmemleak.

This patch fixes it by skipping the walker and directly
deleting these filter results so we don't miss any filter
result.

As a result of this change, we have to initialize exts->net
properly in tcindex_alloc_perfect_hash(). For net-next, we
need to consider whether we should initialize ->net in
tcf_exts_init() instead, before that just directly test
CONFIG_NET_CLS_ACT=y.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8015d93e

net/sched/cls_tcindex.c

+30 −16
Original line number Diff line number Diff line
@@ -221,14 +221,6 @@ static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last, 
	return 0;

}



static int tcindex_destroy_element(struct tcf_proto *tp,

				   void *arg, struct tcf_walker *walker)

{

	bool last;



	return tcindex_delete(tp, arg, &last, NULL);

}



static void tcindex_destroy_work(struct work_struct *work)

{

	struct tcindex_data *p = container_of(to_rcu_work(work),
@@ -279,7 +271,7 @@ static void tcindex_free_perfect_hash(struct tcindex_data *cp) 
	kfree(cp->perfect);

}



static int tcindex_alloc_perfect_hash(struct tcindex_data *cp)

static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)

{

	int i, err = 0;
@@ -293,6 +285,9 @@ static int tcindex_alloc_perfect_hash(struct tcindex_data *cp) 
				    TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);

		if (err < 0)

			goto errout;

#ifdef CONFIG_NET_CLS_ACT

		cp->perfect[i].exts.net = net;

#endif

	}



	return 0;
@@ -341,7 +336,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, 
	if (p->perfect) {

		int i;



		if (tcindex_alloc_perfect_hash(cp) < 0)

		if (tcindex_alloc_perfect_hash(net, cp) < 0)

			goto errout;

		for (i = 0; i < cp->hash; i++)

			cp->perfect[i].res = p->perfect[i].res;
@@ -410,7 +405,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, 
	err = -ENOMEM;

	if (!cp->perfect && !cp->h) {

		if (valid_perfect_hash(cp)) {

			if (tcindex_alloc_perfect_hash(cp) < 0)

			if (tcindex_alloc_perfect_hash(net, cp) < 0)

				goto errout_alloc;

			balloc = 1;

		} else {
@@ -566,13 +561,32 @@ static void tcindex_destroy(struct tcf_proto *tp, 
			    struct netlink_ext_ack *extack)

{

	struct tcindex_data *p = rtnl_dereference(tp->root);

	struct tcf_walker walker;

	int i;



	pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);

	walker.count = 0;

	walker.skip = 0;

	walker.fn = tcindex_destroy_element;

	tcindex_walk(tp, &walker);



	if (p->perfect) {

		for (i = 0; i < p->hash; i++) {

			struct tcindex_filter_result *r = p->perfect + i;



			tcf_unbind_filter(tp, &r->res);

			if (tcf_exts_get_net(&r->exts))

				tcf_queue_work(&r->rwork,

					       tcindex_destroy_rexts_work);

			else

				__tcindex_destroy_rexts(r);

		}

	}



	for (i = 0; p->h && i < p->hash; i++) {

		struct tcindex_filter *f, *next;

		bool last;



		for (f = rtnl_dereference(p->h[i]); f; f = next) {

			next = rtnl_dereference(f->next);

			tcindex_delete(tp, &f->result, &last, NULL);

		}

	}



	tcf_queue_work(&p->rwork, tcindex_destroy_work);

}