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: 8d55373875 ("net/sched/hfsc: allocate tcf block for hfsc root class")
Fixes: 87b60cfacf ("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>
This commit is contained in:
Nikolay Aleksandrov 2017-08-30 12:49:00 +03:00 committed by David S. Miller
parent 32db864d33
commit 3bdac362a2

View file

@ -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