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net/sched: sch_taprio: reset child qdiscs before freeing them 

[ Upstream commit 44d4775ca5 ]

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: 5a781ccbd1 ("tc: Add support for configuring the taprio scheduler")
Link: https://syzkaller.appspot.com/bug?id=f362872379bf8f0017fb667c1ab158f2d1e764ae
Reported-by: syzbot+8971da381fb5a31f542d@syzkaller.appspotmail.com
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Link: https://lore.kernel.org/r/63b6d79b0e830ebb0283e020db4df3cdfdfb2b94.1608142843.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Davide Caratti 2020-12-16 19:33:29 +01:00 committed by Greg Kroah-Hartman
parent dfce803cd8
commit c71c512f4a
1 changed files with 16 additions and 1 deletions
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17
net/sched/sch_taprio.c
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@ -1597,6 +1597,21 @@ free_sched:
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,