There is a reproducible sequence from the userland that will trigger a WARN_ON() condition in taprio_get_start_time, which causes kernel to panic if configured as "panic_on_warn". Remove this WARN_ON() to prevent kernel from crashing by userland-initiated syscalls.
Reported as bug on syzkaller: https://syzkaller.appspot.com/bug?extid=d50710fd0873a9c6b40c Reported-by: syzbot+d50710fd0873a9c6b...@syzkaller.appspotmail.com Signed-off-by: Du Cheng <duche...@gmail.com> --- changelog: v1: Discussion https://lore.kernel.org/netdev/YHfwUmFODUHx8G5W@carbon/T/ v2: fix typo net/sched/sch_taprio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 8287894541e3..33a829c1ba9b 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -996,7 +996,7 @@ static int taprio_get_start_time(struct Qdisc *sch, * something went really wrong. In that case, we should warn about this * inconsistent state and return error. */ - if (WARN_ON(!cycle)) + if (!cycle) return -EFAULT; /* Schedule the start time for the beginning of the next -- 2.30.2
