INFO: task kworker/u8:0:12 blocked for more than 154 seconds.
      Not tainted 6.16.0-rc1-syzkaller-00236-g8c6bc74c7f89 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:23208 pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
 linkwatch_event+0xe/0x60 net/core/link_watch.c:303
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
2 locks held by init/1:
3 locks held by kworker/0:1/10:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc900000f7bc0 (drain_vmap_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900000f7bc0 (drain_vmap_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8e242568 (vmap_purge_lock){+.+.}-{4:4}, at: drain_vmap_area_work+0x17/0x40 mm/vmalloc.c:2381
3 locks held by kworker/u8:0/12:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90000117bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000117bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/u8:3/37:
2 locks held by kswapd1/87:
4 locks held by kworker/u8:6/3513:
 #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9000b917bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000b917bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f4f12d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
 #3: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1676
3 locks held by klogd/5183:
3 locks held by udevd/5194:
2 locks held by dhcpcd/5489:
 #0: ffff8880273216d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xb8/0xe20 net/netlink/af_netlink.c:2255
 #1: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6812
2 locks held by crond/5569:
 #0: ffff88807c8a7560 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:431 [inline]
 #0: ffff88807c8a7560 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:188 [inline]
 #0: ffff88807c8a7560 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:248
 #1: ffffffff8e245940 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4118 [inline]
 #1: ffffffff8e245940 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xb8/0x300 mm/page_alloc.c:4143
2 locks held by getty/5589:
 #0: ffff888030d1b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by sshd-session/5810:
2 locks held by kworker/0:6/5922:
2 locks held by kworker/u8:10/6010:
3 locks held by kworker/u8:12/6589:
 #0: ffff8880300b6948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff8880300b6948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9000dc7fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000dc7fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738
1 lock held by syz.4.196/6776:
 #0: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
 #0: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
6 locks held by syz.0.866/9329:
1 lock held by syz.0.866/9330:
 #0: ffff888024e260a8 (&ctx->uring_lock){+.+.}-{4:4}, at: __io_uring_add_tctx_node+0x20e/0x4e0 io_uring/tctx.c:139
3 locks held by syz-executor/9389:
3 locks held by syz-executor/9399:
1 lock held by syz-executor/9401:
 #0: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
 #0: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
1 lock held by syz-executor/9403:
 #0: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
 #0: ffffffff8f4fdec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc1-syzkaller-00236-g8c6bc74c7f89 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5183 Comm: klogd Not tainted 6.16.0-rc1-syzkaller-00236-g8c6bc74c7f89 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 8e 34 80 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cf 87 e1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0000:ffffc900033467d0 EFLAGS: 00000002
RAX: 1ffffffff33b2a00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff99d957d0 R08: ffff888024d10237 R09: 1ffff110049a2046
R10: dffffc0000000000 R11: ffffffff85402660 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99d95540 R15: 0000000000000000
FS:  00007fd42c881c80(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd9ac0d9ae8 CR3: 000000007c57a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:137 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
 wait_for_lsr+0x19e/0x2f0 drivers/tty/serial/8250/8250_port.c:2094
 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
 serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
 console_emit_next_record kernel/printk/printk.c:3138 [inline]
 console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 dump_unreclaimable_slab+0x112/0x150 mm/slab_common.c:1157
 dump_header+0x39e/0x480 mm/oom_kill.c:473
 oom_kill_process+0x3b6/0x950 mm/oom_kill.c:1040
 out_of_memory+0xfe1/0x12a0 mm/oom_kill.c:1160
 __alloc_pages_may_oom+0x1f2/0x330 mm/page_alloc.c:3836
 __alloc_pages_slowpath+0x706/0xce0 mm/page_alloc.c:4646
 __alloc_frozen_pages_noprof+0x319/0x370 mm/page_alloc.c:4972
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2438
 __read_swap_cache_async+0x166/0x510 mm/swap_state.c:400
 swap_cluster_readahead+0x4cf/0x5f0 mm/swap_state.c:632
 swapin_readahead+0x17d/0xb50 mm/swap_state.c:811
 do_swap_page+0x525/0x5ac0 mm/memory.c:4623
 handle_pte_fault mm/memory.c:6092 [inline]
 __handle_mm_fault+0xf3e/0x5620 mm/memory.c:6232
 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6401
 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__get_user_8+0x14/0x30 arch/x86/lib/getuser.S:103
Code: ca e9 00 f0 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 ba 00 f0 ff ff ff 7f 00 00 48 39 d0 48 0f 47 c2 0f 01 cb <48> 8b 10 31 c0 0f 01 ca e9 cf ef 03 00 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc90003347d98 EFLAGS: 00050287
RAX: 00007fd42c881ae8 RBX: ffff88807c7bd170 RCX: bb59c30afbe68100
RDX: 00007ffffffff000 RSI: ffffffff8db5a47d RDI: ffffffff8be1b700
RBP: ffffc90003347ec0 R08: 0000000000000000 R09: ffffffff820a4470
R10: dffffc0000000000 R11: fffffbfff1f3fc5f R12: dffffc0000000000
R13: ffffc90003347fd8 R14: 00007fd42c881ae8 R15: ffff88807c7bbc00
 rseq_get_rseq_cs_ptr_val kernel/rseq.c:248 [inline]
 rseq_get_rseq_cs kernel/rseq.c:270 [inline]
 rseq_ip_fixup kernel/rseq.c:390 [inline]
 __rseq_handle_notify_resume+0x137/0x11f0 kernel/rseq.c:438
 rseq_handle_notify_resume include/linux/rseq.h:38 [inline]
 resume_user_mode_work include/linux/resume_user_mode.h:62 [inline]
 exit_to_user_mode_loop+0xc2/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd42c9d1407
Code: Unable to access opcode bytes at 0x7fd42c9d13dd.
RSP: 002b:00007fff8cd6c7d0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffff91 RBX: 00007fd42c881c80 RCX: 00007fd42c9d1407
RDX: 000000000000005d RSI: 00007fff8cd6c910 RDI: 0000000000000003
RBP: 00007fff8cd6cd40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007fff8cd6cd58
R13: 00007fff8cd6c910 R14: 0000000000000042 R15: 00007fff8cd6c910
 </TASK>