rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...0: (174 ticks this GP) idle=02ec/1/0x4000000000000000 softirq=78280/78280 fqs=2110 rcu: hardirqs softirqs csw/system rcu: number: 0 0 0 rcu: cputime: 0 0 0 ==> 52500(ms) rcu: (detected by 1, t=10505 jiffies, g=82733, q=512623 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5246 Comm: kworker/0:2 Not tainted 6.13.0-rc1-syzkaller-gd8d936c51388 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 01 f9 0b ff eb a0 e8 8a f9 0b RSP: 0018:ffffc90000007328 EFLAGS: 00000002 RAX: 0000000000000020 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff82a96335 RDI: ffffffff93640960 RBP: ffffffff93640920 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 000000000000000e R12: 0000000000000000 R13: 0000000000000020 R14: ffffffff82a962d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f30c3506038 CR3: 0000000008ca0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3341 [inline] serial8250_console_write+0xf9e/0x17c0 drivers/tty/serial/8250/8250_port.c:3412 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:86 _printk+0xc8/0x100 kernel/printk/printk.c:2457 __show_regs+0x2a/0x750 arch/x86/kernel/process_64.c:76 show_trace_log_lvl+0x26c/0x3d0 arch/x86/kernel/dumpstack.c:301 sched_show_task kernel/sched/core.c:7711 [inline] sched_show_task+0x3f0/0x5f0 kernel/sched/core.c:7686 show_state_filter+0xee/0x320 kernel/sched/core.c:7756 k_spec drivers/tty/vt/keyboard.c:667 [inline] k_spec+0xed/0x150 drivers/tty/vt/keyboard.c:656 kbd_keycode drivers/tty/vt/keyboard.c:1522 [inline] kbd_event+0xcbd/0x17a0 drivers/tty/vt/keyboard.c:1541 input_handle_events_default+0x116/0x1b0 drivers/input/input.c:2646 input_pass_values+0x738/0x880 drivers/input/input.c:126 input_event_dispose drivers/input/input.c:341 [inline] input_handle_event+0xf0b/0x14d0 drivers/input/input.c:369 input_repeat_key+0x251/0x340 drivers/input/input.c:2321 call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers+0x6e8/0x930 kernel/time/timer.c:2418 __run_timer_base kernel/time/timer.c:2430 [inline] __run_timer_base kernel/time/timer.c:2422 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2439 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2449 handle_softirqs+0x206/0x8d0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:655 irq_exit_rcu+0x9/0x30 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0x9a4/0xc60 kernel/printk/printk.c:3211 Code: 00 e8 90 de 27 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 1e 39 20 00 48 85 db 0f 85 55 01 00 00 e8 a0 36 20 00 fb 4c 89 e0 <48> c1 e8 03 42 80 3c 38 00 0f 84 11 ff ff ff 4c 89 e7 e8 25 41 7a RSP: 0018:ffffc9000246f4b8 EFLAGS: 00000246 RAX: ffffffff893a7798 RBX: 0000000000000000 RCX: ffffc9000fbc5000 RDX: 0000000000100000 RSI: ffffffff813b1bc0 RDI: 0000000000000007 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000008 R12: ffffffff893a7798 R13: ffffffff893a7740 R14: ffffc9000246f548 R15: dffffc0000000000 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 dev_vprintk_emit drivers/base/core.c:4935 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4946 __dev_printk+0xf5/0x270 drivers/base/core.c:4958 _dev_err+0xe5/0x120 drivers/base/core.c:5001 hub_port_init+0x1323/0x3ab0 drivers/usb/core/hub.c:5070 hub_port_connect drivers/usb/core/hub.c:5450 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x2c16/0x4f40 drivers/usb/core/hub.c:5903 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f8d8821f860 RCX: 00007f8d8812ea90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007f8d8821f860 R08: 0000000000000001 R09: 748a19ab649a8e99 R10: 00007ffe0bd04840 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f8d88223658 R15: 0000000000000001 task:kworker/u8:7 state:R running task stack:28752 pid:14532 tgid:14532 ppid:10792 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x102c/0x34b0 kernel/sched/core.c:6756 do_task_dead+0xd6/0x110 kernel/sched/core.c:6772 do_exit+0x1de7/0x2ce0 kernel/exit.c:989 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdf4e185a90 RSP: 002b:00007ffd4bbce068 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fdf4e276860 RCX: 00007fdf4e185a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007fdf4e276860 R08: 0000000000000001 R09: 5e150f0ed30d1dd3 R10: 00007ffd4bbcdf20 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fdf4e27a658 R15: 0000000000000001 Showing all locks held in the system: 4 locks held by kworker/u8:4/48: #0: ffff888100abb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90000527d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff8a1853d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xbb/0xb40 net/core/net_namespace.c:586 #3: ffffffff88ec7d38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 2 locks held by getty/2900: #0: ffff8881122c60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4} , at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:4/5222: #0: ffff888100080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000202fd80 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff88ec7c00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x700 kernel/rcu/tree.c:4565 10 locks held by kworker/0:2/5246: #0: ffff88810668f548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000246fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810b32f190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff88810b32f190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88810b3b2508 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff88810b3b2508 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] #3: ffff88810b3b2508 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #3: ffff88810b3b2508 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5821 [inline] #3: ffff88810b3b2508 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x28aa/0x4f40 drivers/usb/core/hub.c:5903 #4: ffff888107f60f68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] #4: ffff888107f60f68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #4: ffff888107f60f68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5821 [inline] #4: ffff888107f60f68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x28d0/0x4f40 drivers/usb/core/hub.c:5903 #5: ffffc90000007ca8 ((&dev->timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x610 kernel/time/timer.c:1790 #6: ffff888113bbf230 (&dev->event_lock){..-.}-{3:3}, at: input_repeat_key+0x29/0x340 drivers/input/input.c:2313 #7: ffffffff88ebc400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #7: ffffffff88ebc400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #7: ffffffff88ebc400 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x8b/0x880 drivers/input/input.c:118 #8: ffffffff89391ab8 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #8: ffffffff89391ab8 (kbd_event_lock){..-.}-{3:3}, at: kbd_event+0x8a/0x17a0 drivers/tty/vt/keyboard.c:1535 #9: ffffffff88ebc400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #9: ffffffff88ebc400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #9: ffffffff88ebc400 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 4 locks held by kworker/0:3/5258: 5 locks held by kworker/0:4/5267: 5 locks held by kworker/0:0/8649: 1 lock held by syz-executor/10449: #0: ffffffff88ec7d38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 =============================================