INFO: task syz.8.5941:28899 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.5941      state:D stack:27672 pid:28899 tgid:28898 ppid:21509  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7005
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 sync_bdevs+0x153/0x480 block/bdev.c:1304
 ksys_sync+0xb0/0xf0 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f48d959c799
RSP: 002b:00007f48da37e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f48d9815fa0 RCX: 00007f48d959c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f48d9815fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f48d9816038 R14: 00007f48d9815fa0 R15: 00007fffdcc19d98
 </TASK>
INFO: task syz.8.5941:28900 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.5941      state:D stack:28136 pid:28900 tgid:28898 ppid:21509  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7005
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 sync_bdevs+0x153/0x480 block/bdev.c:1304
 ksys_sync+0xb0/0xf0 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f48d959c799
RSP: 002b:00007f48d77f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f48d9816090 RCX: 00007f48d959c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f48d9816090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f48d9816128 R14: 00007f48d9816090 R15: 00007fffdcc19d98
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
5 locks held by kworker/0:2/792:
 #0: ffff888022e9e548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
 #1: ffffc90004117d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
 #2: ffff88802b738198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88802b738198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: ffff888022ae8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff888022ae8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
 #4: ffff88802bde3160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #4: ffff88802bde3160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
2 locks held by getty/5566:
 #0: ffff888038f620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by udevd/5822:
 #0: ffff888027bf0358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by syz.8.5941/28899:
 #0: ffff888027bf0358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
1 lock held by syz.8.5941/28900:
 #0: ffff888027bf0358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xd25/0x1050 kernel/hung_task.c:515
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 792 Comm: kworker/0:2 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 eb fe e2 f5 cc
RSP: 0018:ffffc90000007c60 EFLAGS: 00000046
RAX: 0000000080010004 RBX: ffff88805c2f2a40 RCX: ffffffff8b8aa118
RDX: ffff8880273a0000 RSI: ffffffff8b8aa228 RDI: ffff88805c2f2a60
RBP: ffff8880b843baa8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88805c2f2a58
R13: ffff88805c2f2a58 R14: ffff88805c2f2a60 R15: ffff88805c2f2a58
FS:  0000000000000000(0000) GS:ffff888124345000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30608ff8 CR3: 000000007e49a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 plist_check_head lib/plist.c:60 [inline]
 plist_del+0x308/0x510 lib/plist.c:142
 enqueue_pushable_task+0x2d/0x3b0 kernel/sched/rt.c:399
 enqueue_task+0x74/0x4f0 kernel/sched/core.c:2107
 activate_task kernel/sched/core.c:2147 [inline]
 ttwu_do_activate+0x176/0x7c0 kernel/sched/core.c:3667
 ttwu_queue kernel/sched/core.c:3918 [inline]
 try_to_wake_up+0xc48/0x1a80 kernel/sched/core.c:4242
 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:2021
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849
 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1911
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x490 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x553/0x6b0 kernel/printk/printk.c:2478
Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 48 10 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 16 0b 21 00 48 85 ed 0f 85 27 01 00 00 <e8> 28 10 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc90004116a98 EFLAGS: 00000246
RAX: 0000000000100000 RBX: 000000000000004d RCX: ffffc9001aa49000
RDX: 0000000000100000 RSI: ffffffff81e7a3d4 RDI: ffff8880273a0000
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000822d55
R13: 0000000000000200 R14: ffff88801feec980 R15: ffffc90004116c60
 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4913
 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4924
 __dev_printk+0xcb/0x100 drivers/base/core.c:4936
 _dev_info+0xef/0x127 drivers/base/core.c:4982
 mceusb_dev_probe+0x1f14/0x37c0 drivers/media/rc/mceusb.c:1809
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:583 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:661
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:803
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:833
 __device_attach_driver+0x1ff/0x3e0 drivers/base/dd.c:961
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1033
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x64/0x160 drivers/base/bus.c:574
 device_add+0x11d9/0x1950 drivers/base/core.c:3689
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2208
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:583 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:661
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:803
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:833
 __device_attach_driver+0x1ff/0x3e0 drivers/base/dd.c:961
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1033
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x64/0x160 drivers/base/bus.c:574
 device_add+0x11d9/0x1950 drivers/base/core.c:3689
 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
 process_scheduled_works kernel/workqueue.c:3358 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>