On Sun, Jul 21, 2024 at 06:36:01AM -0700, syzbot wrote: > syzbot has bisected this issue to: > > commit a7f3813e589fd8e2834720829a47b5eb914a9afe > Author: Marcello Sylvester Bauer <sylv@xxxxxxx> > Date: Thu Apr 11 14:51:28 2024 +0000 > > usb: gadget: dummy_hcd: Switch to hrtimer transfer scheduler > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12d54f2d980000 > start commit: d35b2284e966 Add linux-next specific files for 20240607 > git tree: linux-next > final oops: https://syzkaller.appspot.com/x/report.txt?x=11d54f2d980000 > console output: https://syzkaller.appspot.com/x/log.txt?x=16d54f2d980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=d8bf5cd6bcca7343 > dashboard link: https://syzkaller.appspot.com/bug?extid=edd9fe0d3a65b14588d5 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10905c26980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1122da8c980000 > > Reported-by: syzbot+edd9fe0d3a65b14588d5@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: a7f3813e589f ("usb: gadget: dummy_hcd: Switch to hrtimer transfer scheduler") > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection Let's try again to see if Marcello's patch fixes the problem. The first try had a typo. Alan Stern #syz test: linux-next d35b2284e966 --- a/drivers/usb/gadget/udc/dummy_hcd.c +++ b/drivers/usb/gadget/udc/dummy_hcd.c @@ -1304,7 +1304,7 @@ static int dummy_urb_enqueue( /* kick the scheduler, it'll do the rest */ if (!hrtimer_active(&dum_hcd->timer)) - hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), HRTIMER_MODE_REL); + hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), HRTIMER_MODE_REL_SOFT); done: spin_unlock_irqrestore(&dum_hcd->dum->lock, flags); @@ -1325,7 +1325,7 @@ static int dummy_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) rc = usb_hcd_check_unlink_urb(hcd, urb, status); if (!rc && dum_hcd->rh_state != DUMMY_RH_RUNNING && !list_empty(&dum_hcd->urbp_list)) - hrtimer_start(&dum_hcd->timer, ns_to_ktime(0), HRTIMER_MODE_REL); + hrtimer_start(&dum_hcd->timer, ns_to_ktime(0), HRTIMER_MODE_REL_SOFT); spin_unlock_irqrestore(&dum_hcd->dum->lock, flags); return rc; @@ -1995,7 +1995,7 @@ static enum hrtimer_restart dummy_timer(struct hrtimer *t) dum_hcd->udev = NULL; } else if (dum_hcd->rh_state == DUMMY_RH_RUNNING) { /* want a 1 msec delay here */ - hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), HRTIMER_MODE_REL); + hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), HRTIMER_MODE_REL_SOFT); } spin_unlock_irqrestore(&dum->lock, flags); @@ -2389,7 +2389,7 @@ static int dummy_bus_resume(struct usb_hcd *hcd) dum_hcd->rh_state = DUMMY_RH_RUNNING; set_link_state(dum_hcd); if (!list_empty(&dum_hcd->urbp_list)) - hrtimer_start(&dum_hcd->timer, ns_to_ktime(0), HRTIMER_MODE_REL); + hrtimer_start(&dum_hcd->timer, ns_to_ktime(0), HRTIMER_MODE_REL_SOFT); hcd->state = HC_STATE_RUNNING; } spin_unlock_irq(&dum_hcd->dum->lock); @@ -2467,7 +2467,7 @@ static DEVICE_ATTR_RO(urbs); static int dummy_start_ss(struct dummy_hcd *dum_hcd) { - hrtimer_init(&dum_hcd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&dum_hcd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); dum_hcd->timer.function = dummy_timer; dum_hcd->rh_state = DUMMY_RH_RUNNING; dum_hcd->stream_en_ep = 0; @@ -2497,7 +2497,7 @@ static int dummy_start(struct usb_hcd *hcd) return dummy_start_ss(dum_hcd); spin_lock_init(&dum_hcd->dum->lock); - hrtimer_init(&dum_hcd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&dum_hcd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); dum_hcd->timer.function = dummy_timer; dum_hcd->rh_state = DUMMY_RH_RUNNING; -- 2.45.2