INFO: task syz.2.1476:8903 blocked for more than 143 seconds.
      Not tainted 5.15.178-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1476      state:D stack:27896 pid: 8903 ppid:  4168 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6515
 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x9a/0x2e0 kernel/locking/rwsem.c:1500
 iterate_supers+0xac/0x1e0 fs/super.c:716
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1ae6b93de9
RSP: 002b:00007f1ae49fd038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1ae6dacfa0 RCX: 00007f1ae6b93de9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1ae6dacfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1ae6dacfa0 R15: 00007ffdea66cfb8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3926:
 #0: ffff88814cd9a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025c62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:3/4158:
 #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000315fd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
3 locks held by kworker/0:4/4212:
 #0: ffff8881421ae538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000313fd20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff88802488c220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #2: ffff88802488c220 (&dev->mutex){....}-{3:3}, at: hub_event+0x208/0x54c0 drivers/usb/core/hub.c:5771
4 locks held by kworker/u4:6/4262:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000323fd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
 #3: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #3: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
3 locks held by kworker/u4:7/4270:
4 locks held by +}[@/7889:
1 lock held by syz.2.1476/8903:
 #0: ffff88801adae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716
3 locks held by kworker/1:17/9341:
 #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000350fd20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff888076dea240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1480
4 locks held by udevd/9597:
 #0: ffff888079cd0540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xae/0xd10 fs/seq_file.c:182
 #1: ffff88806115bc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x50/0x3b0 fs/kernfs/file.c:112
 #2: ffff888045da3e88 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x6f/0x3b0 fs/kernfs/file.c:113
 #3: ffff88807d021220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #3: ffff88807d021220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17e/0x340 drivers/base/core.c:2408
1 lock held by syz.3.1712/9659:
 #0: ffff88801adae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716
1 lock held by syz.8.2078/11119:
 #0: ffff88801adae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716
2 locks held by syz-executor/11347:
 #0: ffffffff8dca0290 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802
 #1: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x28/0x540 net/wireless/nl80211.c:14964

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4212 Comm: kworker/0:4 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_in+0x72/0xb0 drivers/tty/serial/8250/8250_port.c:461
Code: 14 55 fa fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 55 3d 44 fd 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 89 e9 80 e1 07 38 c1 7c ad 48 89 ef
RSP: 0018:ffffc9000313e4d0 EFLAGS: 00000002
RAX: 1ffffffff2db7360 RBX: ffffffff96db9a00 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000092981 RDI: 0000000000092982
RBP: 0000000000000000 R08: ffffffff84863072 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000034
R13: ffffffff96db99c0 R14: 00000000000003fd R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3081bff8 CR3: 0000000025877000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:116 [inline]
 wait_for_xmitr+0x51/0x260 drivers/tty/serial/8250/8250_port.c:2069
 serial8250_console_putchar+0x19/0x50 drivers/tty/serial/8250/8250_port.c:3301
 uart_console_write+0xa9/0x100 drivers/tty/serial/serial_core.c:1981
 serial8250_console_write+0xc8e/0x1180 drivers/tty/serial/8250/8250_port.c:3378
 console_unlock+0xced/0x12b0 kernel/printk/printk.c:2744
 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
 dev_vprintk_emit+0x2aa/0x330 drivers/base/core.c:4638
 dev_printk_emit+0xd9/0x120 drivers/base/core.c:4649
 _dev_info+0x11e/0x170 drivers/base/core.c:4707
 rtl871x_load_fw+0x8d/0x110 drivers/staging/rtl8712/hal_init.c:72
 r871xu_drv_init+0x1600/0x1f70 drivers/staging/rtl8712/usb_intf.c:567
 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396
 really_probe+0x24e/0xb60 drivers/base/dd.c:595
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:755
 driver_probe_device+0x50/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b9/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:979
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3412
 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293
 really_probe+0x24e/0xb60 drivers/base/dd.c:595
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:755
 driver_probe_device+0x50/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b9/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:979
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3412
 usb_new_device+0xc21/0x18f0 drivers/usb/core/hub.c:2593
 hub_port_connect drivers/usb/core/hub.c:5457 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5597 [inline]
 port_event drivers/usb/core/hub.c:5743 [inline]
 hub_event+0x2cdf/0x54c0 drivers/usb/core/hub.c:5825
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>