rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-...D } 2651 jiffies s: 103733 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: running task NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7599 Comm: udevd Not tainted 6.12.0-rc1-syzkaller-00027-g4a9fe2a8ac53 #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 f1 eb 0d ff eb a0 e8 7a ec 0d RSP: 0018:ffffc90000007028 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff82a076c5 RDI: ffffffff936356a0 RBP: ffffffff93635660 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff936356b0 R15: 0000000000000034 FS: 00007f82f57a7c80(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2fa04b CR3: 000000012b57c000 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_clear_IER+0x9b/0xc0 drivers/tty/serial/8250/8250_port.c:699 serial8250_console_write+0x243/0x17c0 drivers/tty/serial/8250/8250_port.c:3358 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 sched_show_task kernel/sched/core.c:7568 [inline] sched_show_task+0x4d2/0x5f0 kernel/sched/core.c:7557 show_state_filter+0xee/0x320 kernel/sched/core.c:7627 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+0x17c3/0x38d0 drivers/usb/gadget/udc/dummy_hcd.c:1988 __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:1037 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_latency_start kernel/sched/core.c:5766 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:5761 [inline] RIP: 0010:preempt_count_add+0x82/0x150 kernel/sched/core.c:5789 Code: 7e 25 ff ff ff 7f 39 c3 74 07 5b 5d c3 cc cc cc cc 48 8b 5c 24 10 48 89 df e8 ea 64 0b 00 85 c0 75 38 65 48 8b 2d 8e 84 db 7e <48> 8d bd 78 14 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc90002437930 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff81157de1 RCX: 1ffffffff2695330 RDX: 0000000000000000 RSI: ffffffff81ae3547 RDI: ffffffff81157de1 RBP: ffff88813e568000 R08: ffffc900024379ec R09: ffffffff8abb31fc R10: ffffc900024379b8 R11: 000000000000ae61 R12: ffffffff8141dd90 R13: ffffc900024379b8 R14: 0000000000000000 R15: ffff88813e568000 unwind_next_frame+0xb1/0x20c0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x130/0x480 mm/slub.c:4728 do_delayed_call include/linux/delayed_call.h:28 [inline] vfs_readlink+0x149/0x380 fs/namei.c:5272 do_readlinkat+0x24c/0x390 fs/stat.c:551 __do_sys_readlink fs/stat.c:574 [inline] __se_sys_readlink fs/stat.c:571 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:571 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: 0033:0x7f82f58d3d47 Code: 73 01 c3 48 8b 0d e1 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 90 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe238202d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00005621627175e0 RCX: 00007f82f58d3d47 RDX: 0000000000000400 RSI: 00007ffe238206e8 RDI: 00007ffe238202e8 RBP: 00007ffe23820b28 R08: 0000562126c061fd R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000202 R12: 0000000000000200 R13: 00007ffe238206e8 R14: 00007ffe238202e8 R15: 0000562126c00a04 stack:32568 pid:9349 tgid:9349 ppid:5110 flags:0x00004000 Call Trace: entry_SYSCALL_64_after_hwframe+0x77/0x7f task:modprobe state:R running task stack:24704 pid:9355 tgid:9355 ppid:32311 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6675 do_task_dead+0xd6/0x110 kernel/sched/core.c:6691 do_exit+0x1de7/0x2ce0 kernel/exit.c:990 do_group_exit+0xd3/0x2a0 kernel/exit.c:1088 __do_sys_exit_group kernel/exit.c:1099 [inline] __se_sys_exit_group kernel/exit.c:1097 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1097 x64_sys_call+0x14a9/0x16a0 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: 0033:0x7f9827d79a90 RSP: 002b:00007ffebd5fc8a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f9827e6a860 RCX: 00007f9827d79a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007f9827e6a860 R08: 0000000000000001 R09: 64bd565fa26f63cd R10: 00007ffebd5fc760 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f9827e6e658 R15: 0000000000000001 Showing all locks held in the system: 3 locks held by kworker/0:2/803: 2 locks held by getty/2608: #0: ffff88810ff7f0a0 (&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 5 locks held by kworker/0:7/19102: 1 lock held by udevd/7392: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0x39e/0x5a0 fs/kernfs/dir.c:1141 4 locks held by udevd/7599: #0: ffff88812d171230 (&dev->event_lock){..-.}-{2:2}, at: input_event drivers/input/input.c:397 [inline] #0: ffff88812d171230 (&dev->event_lock){..-.}-{2:2}, at: input_event+0x70/0xa0 drivers/input/input.c:390 #1: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: input_pass_values+0x8b/0x8e0 drivers/input/input.c:118 #2: ffffffff89387ad8 (kbd_event_lock){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffffffff89387ad8 (kbd_event_lock){..-.}-{2:2}, at: kbd_event+0x8a/0x17a0 drivers/tty/vt/keyboard.c:1535 #3: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 1 lock held by udevd/7600: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0x39e/0x5a0 fs/kernfs/dir.c:1141 1 lock held by syz.3.7072/8864: #0: ffffffff88ec6a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 1 lock held by syz.2.7074/8861: #0: ffffffff88ec6a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 =============================================