syzkaller shows that packets can still be dequeued while taprio_destroy()
is running. Let sch_taprio use the reset() function to cancel the advance
timer and drop all skbs from the child qdiscs.
Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler")
Link:
https://syzkaller.appspot.com/bug?id=f362872379bf8f0017fb667c1ab158f2d1e764ae
Reported-by: [email protected]
Signed-off-by: Davide Caratti <[email protected]>
---
net/sched/sch_taprio.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 26fb8a62996b..c74817ec9964 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1597,6 +1597,21 @@ static int taprio_change(struct Qdisc *sch, struct
nlattr *opt,
return err;
}
+static void taprio_reset(struct Qdisc *sch)
+{
+ struct taprio_sched *q = qdisc_priv(sch);
+ struct net_device *dev = qdisc_dev(sch);
+ int i;
+
+ hrtimer_cancel(&q->advance_timer);
+ if (q->qdiscs) {
+ for (i = 0; i < dev->num_tx_queues && q->qdiscs[i]; i++)
+ qdisc_reset(q->qdiscs[i]);
+ }
+ sch->qstats.backlog = 0;
+ sch->q.qlen = 0;
+}
+
static void taprio_destroy(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
@@ -1607,7 +1622,6 @@ static void taprio_destroy(struct Qdisc *sch)
list_del(&q->taprio_list);
spin_unlock(&taprio_list_lock);
- hrtimer_cancel(&q->advance_timer);
taprio_disable_offload(dev, q, NULL);
@@ -1954,6 +1968,7 @@ static struct Qdisc_ops taprio_qdisc_ops __read_mostly = {
.init = taprio_init,
.change = taprio_change,
.destroy = taprio_destroy,
+ .reset = taprio_reset,
.peek = taprio_peek,
.dequeue = taprio_dequeue,
.enqueue = taprio_enqueue,
--
2.29.2
