Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
flat view
From: Eric Dumazet <hidden>
Date: 2021-08-11 07:44:51
On 8/11/21 7:10 AM, 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; for (i = 0; i < mqprio->num_tc; i++) netdev_set_tc_queue(dev, i, mqprio->count[i],
When was the bug added ?
Hint: Please provide a Fixes: tag
taprio_parse_mqprio_opt() already checks :
/* Verify num_tc is not out of max range */
if (qopt->num_tc > TC_MAX_QUEUE) {
NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
return -EINVAL;
}
So what is happening exactly ?