Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
flat view
From: Jakub Kicinski <kuba@kernel.org>
Date: 2021-08-12 17:53:24
On Wed, 11 Aug 2021 13:10:09 +0800 tcs.kernel@gmail.com wrote:
quoted hunk ↗ jump to hunk
From: Haimin Zhang <redacted> syzbot report an array-index-out-of-bounds in taprio_change index 16 is out of range for type '__u16 [16]' that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check the return value of netdev_set_num_tc. Reported-by: <redacted> Signed-off-by: Haimin Zhang <redacted> --- net/sched/sch_taprio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 9c79374..1ab2fc9 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c@@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, taprio_set_picos_per_byte(dev, q); if (mqprio) { - netdev_set_num_tc(dev, mqprio->num_tc); + err = netdev_set_num_tc(dev, mqprio->num_tc); + if (err) + goto free_sched;
taprio_set_picos_per_byte() already got called and applied some of the
changes. It seems like the early return from taprio_parse_mqprio_opt()
if dev->num_tc is non-zero is incorrect. That function is supposed to
validate that mqprio_opt() is correct AFAIU. That would mean:
Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule")
Vinicius - WDYT?
for (i = 0; i < mqprio->num_tc; i++) netdev_set_tc_queue(dev, i, mqprio->count[i],