rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-...D } 2644 jiffies s: 89625 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2547 Comm: udevd Not tainted 6.12.0-rc4-syzkaller-00052-gc6d9e43954bf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:413 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 31 f0 0d ff eb a0 e8 ba f0 0d RSP: 0018:ffffc90000006f58 EFLAGS: 00000002 RAX: 0000000000000032 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff82a08975 RDI: ffffffff93637660 RBP: ffffffff93637620 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000032 R14: ffffffff82a08910 R15: 0000000000000000 FS: 00007fcc57ef8c80(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f644fb813c0 CR3: 0000000116792000 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:3322 [inline] serial8250_console_write+0xf9e/0x17c0 drivers/tty/serial/8250/8250_port.c:3393 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3279 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline] show_trace_log_lvl+0x1b7/0x3d0 arch/x86/kernel/dumpstack.c:285 sched_show_task kernel/sched/core.c:7604 [inline] sched_show_task+0x3f0/0x5f0 kernel/sched/core.c:7579 show_state_filter+0xee/0x320 kernel/sched/core.c:7649 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_handler_events_default+0x116/0x1b0 drivers/input/input.c:2549 input_pass_values+0x777/0x8e0 drivers/input/input.c:126 input_event_dispose drivers/input/input.c:352 [inline] input_handle_event+0xb30/0x14d0 drivers/input/input.c:369 input_event drivers/input/input.c:398 [inline] input_event+0x83/0xa0 drivers/input/input.c:390 hidinput_hid_event+0xa12/0x2410 drivers/hid/hid-input.c:1719 hid_process_event+0x4b7/0x5e0 drivers/hid/hid-core.c:1540 hid_input_array_field+0x535/0x710 drivers/hid/hid-core.c:1652 hid_process_report drivers/hid/hid-core.c:1694 [inline] hid_report_raw_event+0xa02/0x11c0 drivers/hid/hid-core.c:2040 __hid_input_report.constprop.0+0x341/0x440 drivers/hid/hid-core.c:2110 hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:285 __usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734 dummy_timer+0x17f0/0x3930 drivers/usb/gadget/udc/dummy_hcd.c:1993 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1772 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 kernel/softirq.c:637 [inline] irq_exit_rcu+0xac/0x110 kernel/softirq.c:649 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:write_comp_data+0x8b/0x90 kernel/kcov.c:272 Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc9000163f968 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81db270a RDX: ffff8881166a9d40 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888125c98870 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888125c98874 R13: ffff88810179a101 R14: ffff888132e14f00 R15: ffff88810179a228 kernfs_get_active+0xaa/0x180 fs/kernfs/dir.c:439 kernfs_fop_open+0xa2/0xdb0 fs/kernfs/file.c:601 do_dentry_open+0x6cb/0x1390 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 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: 0033:0x7fcc580239a4 Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffe8b2a2e30 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fcc580239a4 RDX: 0000000000080000 RSI: 00007ffe8b2a2f68 RDI: 00000000ffffff9c RBP: 00007ffe8b2a2f68 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 0000561e74738b42 R14: 0000000000000001 R15: 0000000000000000 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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: 0033:0x7f7dc68bfe33 RSP: 002b:00007ffd2b94feb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f7dc75a4620 RCX: 00007f7dc68bfe33 RDX: 000000000000004c RSI: 00007f7dc75a4670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd2b94fed4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f7dc75a4670 R15: 0000000000000000 task:syz-executor state:D stack:26784 pid:5531 tgid:5531 ppid:5528 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 task:syz-executor state:D stack:26784 pid:5575 tgid:5575 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 exp_funnel_lock+0x344/0x3b0 kernel/rcu/tree_exp.h:320 synchronize_rcu_expedited+0x290/0x450 kernel/rcu/tree_exp.h:976 namespace_unlock+0x1b5/0x490 fs/namespace.c:1703 drop_collected_mounts fs/namespace.c:2225 [inline] put_mnt_ns fs/namespace.c:5553 [inline] put_mnt_ns+0xf4/0x130 fs/namespace.c:5549 free_nsproxy+0x47/0x470 kernel/nsproxy.c:193 put_nsproxy include/linux/nsproxy.h:118 [inline] switch_task_namespaces+0xeb/0x100 kernel/nsproxy.c:251 do_exit+0xad8/0x2ce0 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1088 get_signal+0x25fb/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x147/0x260 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f567243dbfb RSP: 002b:00007ffe96bb8aa0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffed RBX: 0000000000000005 RCX: 00007f567243dbfb RDX: 00007ffe96bb8b00 RSI: 0000000000008933 RDI: 0000000000000005 RBP: 00007ffe96bb8b00 R08: 0000000000000008 R09: 00315f6576616c73 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f5673124620 R14: 0000000000000000 R15: 0000000000000000 task:syz-executor state:D stack:26784 pid:5587 tgid:5587 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 exp_funnel_lock+0x344/0x3b0 kernel/rcu/tree_exp.h:320 synchronize_rcu_expedited+0x290/0x450 kernel/rcu/tree_exp.h:976 namespace_unlock+0x1b5/0x490 fs/namespace.c:1703 drop_collected_mounts fs/namespace.c:2225 [inline] put_mnt_ns fs/namespace.c:5553 [inline] put_mnt_ns+0xf4/0x130 fs/namespace.c:5549 free_nsproxy+0x47/0x470 kernel/nsproxy.c:193 put_nsproxy include/linux/nsproxy.h:118 [inline] switch_task_namespaces+0xeb/0x100 kernel/nsproxy.c:251 do_exit+0xad8/0x2ce0 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1088 get_signal+0x25fb/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x147/0x260 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbd9b16dbfb RSP: 002b:00007ffe26318940 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffed RBX: 0000000000000005 RCX: 00007fbd9b16dbfb RDX: 00007ffe263189a0 RSI: 0000000000008933 RDI: 0000000000000005 RBP: 00007ffe263189a0 R08: 0000000000000003 R09: 00315f6576616c73 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007fbd9be54620 R14: 0000000000000000 R15: 0000000000000000 task:syz-executor state:D stack:26048 pid:5592 tgid:5592 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 exp_funnel_lock+0x344/0x3b0 kernel/rcu/tree_exp.h:320 synchronize_rcu_expedited+0x290/0x450 kernel/rcu/tree_exp.h:976 namespace_unlock+0x1b5/0x490 fs/namespace.c:1703 drop_collected_mounts fs/namespace.c:2225 [inline] put_mnt_ns fs/namespace.c:5553 [inline] put_mnt_ns+0xf4/0x130 fs/namespace.c:5549 free_nsproxy+0x47/0x470 kernel/nsproxy.c:193 put_nsproxy include/linux/nsproxy.h:118 [inline] switch_task_namespaces+0xeb/0x100 kernel/nsproxy.c:251 do_exit+0xad8/0x2ce0 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1088 get_signal+0x25fb/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x147/0x260 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8482e9dbfb RSP: 002b:00007ffd80725a20 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffed RBX: 0000000000000005 RCX: 00007f8482e9dbfb RDX: 00007ffd80725a80 RSI: 0000000000008933 RDI: 0000000000000005 RBP: 00007ffd80725a80 R08: 0000000000000001 R09: 00315f6576616c73 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f8483b84620 R14: 0000000000000000 R15: 0000000000000000 task:kworker/u8:4 state:I stack:27040 pid:5595 tgid:5595 ppid:2 flags:0x00004000 Workqueue: 0x0 (events_unbound) Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 worker_thread+0x2de/0xf00 kernel/workqueue.c:3406 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 task:kworker/u8:5 state:I stack:26880 pid:5602 tgid:5602 ppid:2 flags:0x00004000 Workqueue: 0x0 (events_unbound) Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 worker_thread+0x2de/0xf00 kernel/workqueue.c:3406 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 task:kworker/u8:6 state:I stack:30928 pid:5675 tgid:5675 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 worker_thread+0x2de/0xf00 kernel/workqueue.c:3406 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 Showing all locks held in the system: 4 locks held by udevd/2547: #0: ffff88813a773230 (&dev->event_lock){..-.}-{2:2}, at: input_event drivers/input/input.c:397 [inline] #0: ffff88813a773230 (&dev->event_lock){..-.}-{2:2}, at: input_event+0x70/0xa0 drivers/input/input.c:390 #1: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: input_pass_values+0x8b/0x8e0 drivers/input/input.c:118 #2: ffffffff89387a58 (kbd_event_lock){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffffffff89387a58 (kbd_event_lock){..-.}-{2:2}, at: kbd_event+0x8a/0x17a0 drivers/tty/vt/keyboard.c:1535 #3: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 2 locks held by getty/2605: #0: ffff888108ad70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 4 locks held by udevd/31385: #0: ffff888115ce0d58 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811536c888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff8881114820f8 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811377f190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1019 [inline] (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/0:8/2320: #0: ffff888105adf548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90009f3fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810979c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff88810979c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88811377f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88811377f190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88811377d160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88811377d160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffff88810fff5bd8 (&dev->ctrl_urb_lock){+.+.}-{3:3}, at: em28xx_read_reg_req_len+0x142/0x3c0 drivers/media/usb/em28xx/em28xx-core.c:79 1 lock held by syz.4.5933/5524: #0: ffffffff88ec6a38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 1 lock held by syz.1.5934/5520: #0: ffffffff88ec6a38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 =============================================