INFO: task syz.7.6663:29695 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.6663      state:D stack:27912 pid:29695 ppid:25205  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: 0033:0x7f2bb7f5e98e
RSP: 002b:00007f2bb8e4bb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2bb8e4c6c0 RCX: 00007f2bb7f5e98e
RDX: 0000000000101301 RSI: 00007f2bb8e4bc00 RDI: ffffffffffffff9c
RBP: 00007f2bb8e4bc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f2bb8226038 R14: 00007f2bb8225fa0 R15: 00007ffd3259b0b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:7/1128:
 #0: ffff8880b8e3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
 #1: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x21d3/0x4660 kernel/sched/core.c:6696
 #2: ffff8880b8e295d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
 #3: ffffffff9751e468 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6c/0x500 lib/debugobjects.c:747
7 locks held by kworker/0:2/1191:
 #0: ffff88823bd18f38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88823bd18f38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000504fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000504fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff8880252811d8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #2: ffff8880252811d8 (&dev->mutex){....}-{3:3}, at: hub_event+0x188/0x4a80 drivers/usb/core/hub.c:5861
 #3: ffff88807e3831d8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #3: ffff88807e3831d8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1084
 #4: ffff88807d9ee1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #4: ffff88807d9ee1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1084
 #5: ffff88802473d0d0 (i2c_register_adapter){+.+.}-{3:3}, at: i2c_lock_bus include/linux/i2c.h:795 [inline]
 #5: ffff88802473d0d0 (i2c_register_adapter){+.+.}-{3:3}, at: __i2c_lock_bus_helper drivers/i2c/i2c-core.h:46 [inline]
 #5: ffff88802473d0d0 (i2c_register_adapter){+.+.}-{3:3}, at: i2c_transfer+0x11b/0x3a0 drivers/i2c/i2c-core-base.c:2351
 #6: ffff88802473d028 (&d->i2c_mutex){+.+.}-{3:3}, at: dtv5100_i2c_xfer+0x7b/0x610 drivers/media/usb/dvb-usb/dtv5100.c:80
3 locks held by kworker/u4:14/3533:
 #0: ffff88802c1bfd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88802c1bfd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000d677d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000d677d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8e3d6fc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4730
2 locks held by getty/5533:
 #0: ffff88814cc710a0 (&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
4 locks held by udevd/5784:
 #0: ffff8880340b0540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xa1/0xc50 fs/seq_file.c:182
 #1: ffff888069424088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5d/0x410 fs/kernfs/file.c:172
 #2: ffff888072f7cd98 (kn->active#18){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888072f7cd98 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
 #3: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #3: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x21d3/0x4660 kernel/sched/core.c:6696
5 locks held by kworker/u4:8/27378:
 #0: ffff888140045138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888140045138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90004967d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90004967d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8e3c9f90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606
 #3: ffffffff8e3d6fc8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xf2/0xa00 net/core/dev.c:11764
 #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
 #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
6 locks held by kworker/0:8/28305:
1 lock held by syz.7.6663/29695:
 #0: ffff8880252af1d8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #0: ffff8880252af1d8 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x152/0x770 drivers/usb/core/devio.c:1051
3 locks held by syz.2.7115/31360:
 #0: ffff888024d2e070 (&newdev->mutex){+.+.}-{3:3}, at: uinput_ioctl_handler+0xf7/0x1590 drivers/input/misc/uinput.c:921
 #1: ffffffff8de97d28 (input_mutex){+.+.}-{3:3}, at: __input_unregister_device+0x2eb/0x5f0 drivers/input/input.c:2293
 #2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004

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

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>