rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2670 jiffies s: 86521 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9187 Comm: syz-executor.3 Not tainted 6.10.0-rc3-next-20240611-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:406
Code: 60 c8 54 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 11 d7 ba fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc90000a18298 EFLAGS: 00000002
RAX: 1ffffffff295e400 RBX: ffffffff94af23a0 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff853e7f86 R09: 1ffff11003f2e046
R10: dffffc0000000000 R11: ffffffff853e7f40 R12: dffffc0000000000
R13: ffffffff94803bb0 R14: 00000000000003fd R15: dffffc0000000000
FS:  00007f0c9b5bd6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ff44000 CR3: 000000007139c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 serial_in drivers/tty/serial/8250/8250.h:137 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
 wait_for_lsr drivers/tty/serial/8250/8250_port.c:2068 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3315 [inline]
 serial8250_console_write+0x1373/0x1ed0 drivers/tty/serial/8250/8250_port.c:3393
 console_emit_next_record kernel/printk/printk.c:2975 [inline]
 console_flush_all+0x880/0xf50 kernel/printk/printk.c:3047
 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3118
 vprintk_emit+0x7a1/0x900 kernel/printk/printk.c:2420
 _printk+0xd5/0x120 kernel/printk/printk.c:2447
 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline]
 show_trace_log_lvl+0x43a/0x520 arch/x86/kernel/dumpstack.c:285
 sched_show_task+0x578/0x740 kernel/sched/core.c:7432
 report_rtnl_holders+0x1ba/0x2d0 net/core/rtnetlink.c:104
 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792
 expire_timers kernel/time/timer.c:1843 [inline]
 __run_timers kernel/time/timer.c:2417 [inline]
 __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428
 run_timer_base kernel/time/timer.c:2437 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__outw arch/x86/include/asm/shared/io.h:23 [inline]
RIP: 0010:iowrite16+0x37/0x90 lib/iomap.c:213
Code: db dd fc 48 81 fb 00 00 04 00 72 0a e8 82 db dd fc 66 89 2b eb 59 48 81 fb 01 00 01 00 72 0d e8 6f db dd fc 89 e8 89 da 66 ef <eb> 43 8b 2d 11 d2 ee 09 31 ff 89 ee e8 98 df dd fc 85 ed 74 2b e8
RSP: 0018:ffffc9000f5f7928 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000000001c0b0 RCX: 0000000000040000
RDX: 000000000001c0b0 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 0000000000000000 R08: ffffffff8526ebc0 R09: ffff88801f21f198
R10: dffffc0000000000 R11: ffffffff85284300 R12: dffffc0000000000
R13: 000000000000ac20 R14: dffffc0000000000 R15: ffff888016affe00
 vp_notify+0x57/0x80 drivers/virtio/virtio_pci_common.c:45
 virtqueue_notify drivers/virtio/virtio_ring.c:2370 [inline]
 virtqueue_kick+0x39b/0x5c0 drivers/virtio/virtio_ring.c:2393
 request_entropy drivers/char/hw_random/virtio-rng.c:63 [inline]
 copy_data+0x237/0x370 drivers/char/hw_random/virtio-rng.c:74
 virtio_read+0xcb/0x200 drivers/char/hw_random/virtio-rng.c:92
 rng_get_data drivers/char/hw_random/core.c:186 [inline]
 rng_dev_read+0x248/0x6d0 drivers/char/hw_random/core.c:224
 do_loop_readv_writev fs/read_write.c:761 [inline]
 vfs_readv+0x6c6/0xa90 fs/read_write.c:934
 do_preadv fs/read_write.c:1049 [inline]
 __do_sys_preadv fs/read_write.c:1099 [inline]
 __se_sys_preadv fs/read_write.c:1094 [inline]
 __x64_sys_preadv+0x1c7/0x2d0 fs/read_write.c:1094
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c9ba7cea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0c9b5bd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f0c9bbb4120 RCX: 00007f0c9ba7cea9
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007f0c9baebff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f0c9bbb4120 R15: 00007ffea0aef558
 </TASK>
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2200
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb8d47eb9c
RSP: 002b:00007ffc900c4020 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007feb8e0e4620 RCX: 00007feb8d47eb9c
RDX: 0000000000000028 RSI: 00007feb8e0e4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc900c4074 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007feb8e0e4670 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e33a878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #0: ffffffff8e33a878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:959
3 locks held by kworker/0:1/9:
 #0: ffff888015081948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline]
 #0: ffff888015081948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: ffffc900000e7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3224 [inline]
 #1: ffffc900000e7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x91/0xea0 net/wireless/reg.c:2478
4 locks held by kworker/u8:0/11:
 #0: ffff888015ed5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline]
 #0: ffff888015ed5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3224 [inline]
 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: ffffffff8f5e2c90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
 #3: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xa90 net/core/dev.c:11746
1 lock held by khugepaged/37:
 #0: ffffffff8e3ee9a8 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x66/0x560 mm/swap.c:856
3 locks held by kworker/u8:9/2812:
 #0: ffff88802a201948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline]
 #0: ffff88802a201948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: ffffc90009d0fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3224 [inline]
 #1: ffffc90009d0fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4193
2 locks held by kworker/u8:11/2878:
 #0: ffff8880187a7948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline]
 #0: ffff8880187a7948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: ffffc90009cefd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3224 [inline]
 #1: ffffc90009cefd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
2 locks held by getty/4849:
 #0: ffff8880684c80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
2 locks held by syz-fuzzer/5086:
 #0: ffff88801f5100c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x310 fs/file.c:1191
 #1: ffff88805387f1a0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: iterate_dir+0x55b/0x820 fs/readdir.c:101
2 locks held by syz-fuzzer/5106:
 #0: ffff88801f511c48 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x310 fs/file.c:1191
 #1: ffff88807837abd8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: iterate_dir+0x55b/0x820 fs/readdir.c:101
3 locks held by kworker/0:3/5159:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: ffffc900044ffd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3224 [inline]
 #1: ffffc900044ffd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
1 lock held by syz-executor.2/8770:
 #0: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.0/8911:
 #0: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
7 locks held by syz-executor.4/8981:
 #0: ffff88802a112420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2870 [inline]
 #0: ffff88802a112420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586
 #1: ffff888022f38888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325
 #2: ffff888022216968 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326
 #3: ffffffff8eefc428 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166
 #4: ffff88804d5cc0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline]
 #4: ffff88804d5cc0e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1003
 #5: ffff88804d5c9250 (&devlink->lock_key#23){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534
 #6: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:678 [inline]
 #6: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_create+0x408/0x890 drivers/net/netdevsim/netdev.c:750
1 lock held by syz-executor.2/9182:
 #0: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.3/9185:
 #0: ffffffff8e1f00e8 (sched_core_mutex){+.+.}-{3:3}, at: sched_core_get+0x51/0x180 kernel/sched/core.c:421
4 locks held by syz-executor.3/9187:
 #0: ffffffff8eb384a8 (reading_mutex){+.+.}-{3:3}, at: rng_dev_read+0x171/0x6d0 drivers/char/hw_random/core.c:219
 #1: ffffc90000a18c00 (net/core/rtnetlink.c:82){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1789
 #2: ffffffff8e3354a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8e3354a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e3354a0 (rcu_read_lock){....}-{1:2}, at: report_rtnl_holders+0x20/0x2d0 net/core/rtnetlink.c:95
 #3: ffffffff8e3354a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #3: ffffffff8e3354a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #3: ffffffff8e3354a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6689

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