Merge branch 'net-sched-init-failure-fixes'

Nikolay Aleksandrov says:

====================
net/sched: init failure fixes

I went over all qdiscs' init, destroy and reset callbacks and found the
issues fixed in each patch. Mostly they are null pointer dereferences due
to uninitialized timer (qdisc watchdog) or double frees due to ->destroy
cleaning up a second time. There's more information in each patch.
I've tested these by either sending wrong attributes from user-spaces, no
attributes or by simulating memory alloc failure where applicable. Also
tried all of the qdiscs as a default qdisc.

Most of these bugs were present before commit 87b60cfacf9f, I've tried to
include proper fixes tags in each patch.

I haven't included individual patch acks in the set, I'd appreciate it if
you take another look and resend them.
====================

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 26 insertions, 28 deletions

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 780db43..156c8a3 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1139,6 +1139,13 @@ static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
 	struct tc_ratespec *r;
 	int err;
 
+	qdisc_watchdog_init(&q->watchdog, sch);
+	hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
+	q->delay_timer.function = cbq_undelay;
+
+	if (!opt)
+		return -EINVAL;
+
 	err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, NULL);
 	if (err < 0)
 		return err;
@@ -1177,9 +1184,6 @@ static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
 	q->link.avpkt = q->link.allot/2;
 	q->link.minidle = -0x7FFFFFFF;
 
-	qdisc_watchdog_init(&q->watchdog, sch);
-	hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
-	q->delay_timer.function = cbq_undelay;
 	q->toplevel = TC_CBQ_MAXLEVEL;
 	q->now = psched_get_time();
 
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 337f2d6..2c0c05f 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -491,10 +491,8 @@ static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
 		if (!q->flows)
 			return -ENOMEM;
 		q->backlogs = kvzalloc(q->flows_cnt * sizeof(u32), GFP_KERNEL);
-		if (!q->backlogs) {
-			kvfree(q->flows);
+		if (!q->backlogs)
 			return -ENOMEM;
-		}
 		for (i = 0; i < q->flows_cnt; i++) {
 			struct fq_codel_flow *flow = q->flows + i;
 
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index fd15200..11ab8da 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1418,6 +1418,8 @@ hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
 	struct tc_hfsc_qopt *qopt;
 	int err;
 
+	qdisc_watchdog_init(&q->watchdog, sch);
+
 	if (opt == NULL || nla_len(opt) < sizeof(*qopt))
 		return -EINVAL;
 	qopt = nla_data(opt);
@@ -1430,7 +1432,7 @@ hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
 
 	err = tcf_block_get(&q->root.block, &q->root.filter_list);
 	if (err)
-		goto err_tcf;
+		return err;
 
 	q->root.cl_common.classid = sch->handle;
 	q->root.refcnt  = 1;
@@ -1448,13 +1450,7 @@ hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
 	qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
 	qdisc_class_hash_grow(sch, &q->clhash);
 
-	qdisc_watchdog_init(&q->watchdog, sch);
-
 	return 0;
-
-err_tcf:
-	qdisc_class_hash_destroy(&q->clhash);
-	return err;
 }
 
 static int
diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index 51d3ba6..73a53c0 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -477,6 +477,9 @@ static void hhf_destroy(struct Qdisc *sch)
 		kvfree(q->hhf_valid_bits[i]);
 	}
 
+	if (!q->hh_flows)
+		return;
+
 	for (i = 0; i < HH_FLOWS_CNT; i++) {
 		struct hh_flow_state *flow, *next;
 		struct list_head *head = &q->hh_flows[i];
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 5d65ec5..5bf5177 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1017,6 +1017,9 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt)
 	int err;
 	int i;
 
+	qdisc_watchdog_init(&q->watchdog, sch);
+	INIT_WORK(&q->work, htb_work_func);
+
 	if (!opt)
 		return -EINVAL;
 
@@ -1041,8 +1044,6 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt)
 	for (i = 0; i < TC_HTB_NUMPRIO; i++)
 		INIT_LIST_HEAD(q->drops + i);
 
-	qdisc_watchdog_init(&q->watchdog, sch);
-	INIT_WORK(&q->work, htb_work_func);
 	qdisc_skb_head_init(&q->direct_queue);
 
 	if (tb[TCA_HTB_DIRECT_QLEN])
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index f143b7b..9c454f5 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -257,12 +257,7 @@ static int multiq_init(struct Qdisc *sch, struct nlattr *opt)
 	for (i = 0; i < q->max_bands; i++)
 		q->queues[i] = &noop_qdisc;
 
-	err = multiq_tune(sch, opt);
-
-	if (err)
-		kfree(q->queues);
-
-	return err;
+	return multiq_tune(sch, opt);
 }
 
 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb)
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 1b3dd61..14d1724 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -933,11 +933,11 @@ static int netem_init(struct Qdisc *sch, struct nlattr *opt)
 	struct netem_sched_data *q = qdisc_priv(sch);
 	int ret;
 
+	qdisc_watchdog_init(&q->watchdog, sch);
+
 	if (!opt)
 		return -EINVAL;
 
-	qdisc_watchdog_init(&q->watchdog, sch);
-
 	q->loss_model = CLG_RANDOM;
 	ret = netem_change(sch, opt);
 	if (ret)
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 82469ef..fc69fc5 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -716,13 +716,13 @@ static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
 	int i;
 	int err;
 
+	setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
+			       (unsigned long)sch);
+
 	err = tcf_block_get(&q->block, &q->filter_list);
 	if (err)
 		return err;
 
-	setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
-			       (unsigned long)sch);
-
 	for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) {
 		q->dep[i].next = i + SFQ_MAX_FLOWS;
 		q->dep[i].prev = i + SFQ_MAX_FLOWS;
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index b2e4b6a..493270f 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -425,12 +425,13 @@ static int tbf_init(struct Qdisc *sch, struct nlattr *opt)
 {
 	struct tbf_sched_data *q = qdisc_priv(sch);
 
+	qdisc_watchdog_init(&q->watchdog, sch);
+	q->qdisc = &noop_qdisc;
+
 	if (opt == NULL)
 		return -EINVAL;
 
 	q->t_c = ktime_get_ns();
-	qdisc_watchdog_init(&q->watchdog, sch);
-	q->qdisc = &noop_qdisc;
 
 	return tbf_change(sch, opt);
 }