INFO: task syz.8.892:9704 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.892       state:D stack:27912 pid:9704  ppid:7647   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 device_lock include/linux/device.h:1094 [inline]
 usbdev_open+0x152/0x770 drivers/usb/core/devio.c:1051
 chrdev_open+0x58c/0x600 fs/char_dev.c:414
 do_dentry_open+0x880/0x14b0 fs/open.c:929
 do_open fs/namei.c:3683 [inline]
 path_openat+0x284f/0x3270 fs/namei.c:3844
 do_filp_open+0x1f2/0x430 fs/namei.c:3871
 do_sys_openat2+0x134/0x1d0 fs/open.c:1422
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f44ffd5e98e
RSP: 002b:00007f4500bbfb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4500bc06c0 RCX: 00007f44ffd5e98e
RDX: 0000000000002581 RSI: 00007f4500bbfc00 RDI: ffffffffffffff9c
RBP: 00007f4500bbfc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f4500026038 R14: 00007f4500025fa0 R15: 00007ffda9b967a8
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/1:0/23:
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:4/60:
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900015b7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900015b7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
3 locks held by kworker/u4:5/1005:
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000454fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000454fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
 #2: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by kworker/u4:8/2947:
1 lock held by syslogd/5127:
2 locks held by getty/5537:
 #0: ffff88802d3860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by kworker/0:5/5836:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000485fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000485fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805cdf2240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x285/0x32c0 drivers/net/netdevsim/fib.c:1491
1 lock held by syz.8.892/9704:
 #0: ffff8880251101d8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #0: ffff8880251101d8 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x152/0x770 drivers/usb/core/devio.c:1051
2 locks held by kworker/1:6/10091:
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000395fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000395fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
1 lock held by syz.9.1055/10535:
 #0: ffff8880251101d8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #0: ffff8880251101d8 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x152/0x770 drivers/usb/core/devio.c:1051
1 lock held by syz-executor/11091:
 #0: ffffffff8e3d7548 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d7548 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6481
1 lock held by dhcpcd-run-hook/11381:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 60 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:unwind_next_frame+0xc7/0x2990 arch/x86/kernel/unwind_orc.c:482
Code: 00 00 85 ed 74 76 4c 89 74 24 60 48 89 5c 24 18 bf 01 00 00 00 e8 b9 43 21 00 49 8d 6d 50 48 89 e8 48 c1 e8 03 48 89 44 24 58 <42> 80 3c 38 00 74 08 48 89 ef e8 4a 4f a4 00 4c 8b 75 00 4d 85 f6
RSP: 0018:ffffc900015b75d8 EFLAGS: 00000a02
RAX: 1ffff920002b6edf RBX: 1ffff920002b6ed5 RCX: ffffffff972f6403
RDX: ffff88801d279e00 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc900015b76f8 R08: ffffc900015b7770 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900015b7ab0
R13: ffffc900015b76a8 R14: ffffc900015b76e0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa2f6afdfe8 CR3: 000000002e465000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x290 mm/slub.c:3852
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
 nsim_dev_trap_report_work+0x723/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>