sch_hfsc: fix null pointer deref and double free on init failure
Depending on where ->init fails we can get a null pointer deref due to
uninitialized hires timer (watchdog) or a double free of the qdisc hash
because it is already freed by ->destroy().
Fixes: 8d5537387505 ("net/sched/hfsc: allocate tcf block for hfsc root class")
Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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