INFO: task syz.0.934:8134 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.934       state:D stack:26856 pid:8134  tgid:8134  ppid:5844   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5351 [inline]
 __schedule+0x1737/0x4d30 kernel/sched/core.c:6954
 __schedule_loop kernel/sched/core.c:7036 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7051
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1187
 __down_write_common kernel/locking/rwsem.c:1319 [inline]
 __down_write kernel/locking/rwsem.c:1328 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1593
 mmap_write_lock include/linux/mmap_lock.h:356 [inline]
 userfaultfd_release_all+0x15a/0x5e0 mm/userfaultfd.c:2055
 userfaultfd_release+0xe7/0x1b0 fs/userfaultfd.c:868
 __fput+0x449/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f231b38e9a9
RSP: 002b:00007ffe290bc2f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f231b5b7ba0 RCX: 00007f231b38e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f231b5b7ba0 R08: 0000000000000060 R09: 00000006290bc5ef
R10: 00007f231b5b7ac0 R11: 0000000000000246 R12: 00000000000285ec
R13: 00007ffe290bc3f0 R14: ffffffffffffffff R15: 00007ffe290bc410
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
5 locks held by kworker/1:2/927:
 #0: ffff88801e29b148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801e29b148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
 #1: ffffc900035cfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc900035cfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
 #2: ffff888027f3f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #2: ffff888027f3f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
 #3: ffff88802882f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff88802882f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
 #4: ffff888027562160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #4: ffff888027562160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
2 locks held by getty/5609:
 #0: ffff88803389c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by udevd/5858:
 #0: ffff88804b352790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
 #1: ffff88804f806488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154
 #2: ffff888050318788 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155
 #3: ffff88802882f198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
 #3: ffff88802882f198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.0.934/8134:
 #0: ffff88807ac40ca0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:356 [inline]
 #0: ffff88807ac40ca0 (&mm->mmap_lock){++++}-{4:4}, at: userfaultfd_release_all+0x15a/0x5e0 mm/userfaultfd.c:2055
1 lock held by syz.0.934/8135:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11583 Comm: syz.2.2291 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5601 [inline]
RIP: 0010:lock_is_held_type+0xbf/0x190 kernel/locking/lockdep.c:5943
Code: 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 78 02 00 00 85 c0 75 2a 49 ff c7 49 63 85 e8 0a 00 00 48 83 c3 28 49 39 c7 7c d8 <eb> 11 48 c7 c7 50 eb 40 8e 4c 89 fe e8 20 3c 86 f9 eb cb 31 db eb
RSP: 0018:ffffc90004157818 EFLAGS: 00000046
RAX: 0000000000000002 RBX: ffff88802b974740 RCX: 4a143087becf0c00
RDX: 0000000000000000 RSI: ffffffff8e53d960 RDI: ffff88802b974718
RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff819be975
R10: dffffc0000000000 R11: ffffed100572e781 R12: 0000000000000046
R13: ffff88802b973c00 R14: ffffffff8e53d960 R15: 0000000000000002
FS:  0000555585507500(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3361bff8 CR3: 00000000756fc000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lock_is_held include/linux/lockdep.h:249 [inline]
 rcu_read_lock_sched_held+0x89/0x100 kernel/rcu/update.c:126
 task_css_set include/linux/cgroup.h:440 [inline]
 task_dfl_cgroup include/linux/cgroup.h:509 [inline]
 task_psi_group+0x50/0x1a0 kernel/sched/psi.c:893
 psi_account_irqtime+0x23b/0x750 kernel/sched/psi.c:1037
 __schedule+0x871/0x4d30 kernel/sched/core.c:6947
 __schedule_loop kernel/sched/core.c:7036 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7051
 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100
 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline]
 __se_sys_clock_nanosleep+0x2f1/0x380 kernel/time/posix-timers.c:1376
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3735bc1265
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007ffea2ca89d0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007f3735db5fa0 RCX: 00007f3735bc1265
RDX: 00007ffea2ca8a10 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3735db7ba0 R08: 0000000000000000 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000050245
R13: 00007f3735db6080 R14: ffffffffffffffff R15: 00007ffea2ca8b50
 </TASK>