[PATCH net 1/3] taprio: Fix kernel panic in taprio_destroy
From: Vladimir Oltean <olteanv@gmail.com>
Date: 2019-08-28 14:49:02
Subsystem:
cbs/etf/taprio qdiscs, networking [general], tc subsystem, the rest · Maintainers:
Vinicius Costa Gomes, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
taprio_init may fail earlier than this line: list_add(&q->taprio_list, &taprio_list); i.e. due to the net device not being multi queue. Attempting to remove q from the global taprio_list when it is not part of it will result in a kernel panic. Fix it by iterating through the list and removing it only if found. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> --- net/sched/sch_taprio.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 540bde009ea5..f1eea8c68011 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c@@ -1199,12 +1199,17 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, static void taprio_destroy(struct Qdisc *sch) { - struct taprio_sched *q = qdisc_priv(sch); + struct taprio_sched *p, *q = qdisc_priv(sch); struct net_device *dev = qdisc_dev(sch); + struct list_head *pos, *tmp; unsigned int i; spin_lock(&taprio_list_lock); - list_del(&q->taprio_list); + list_for_each_safe(pos, tmp, &taprio_list) { + p = list_entry(pos, struct taprio_sched, taprio_list); + if (p == q) + list_del(&q->taprio_list); + } spin_unlock(&taprio_list_lock); hrtimer_cancel(&q->advance_timer);
--
2.17.1