From 3bdac362a2f89ed3e148fa6f38c5f5d858f50b1a Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Wed, 30 Aug 2017 12:49:00 +0300 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/sched/sch_hfsc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index fd15200f8627..11ab8dace901 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 -- 2.20.1