INFO: task syz.8.1000:10883 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1000 state:D stack:25912 pid:10883 tgid:10882 ppid:9988 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 do_uevent+0x2c3/0x570 fs/dlm/lockspace.c:206 new_lockspace fs/dlm/lockspace.c:583 [inline] __dlm_new_lockspace+0x1aa4/0x2060 fs/dlm/lockspace.c:638 device_create_lockspace+0xc7/0x350 fs/dlm/user.c:414 device_write+0x875/0xed0 fs/dlm/user.c:606 vfs_write+0x29f/0xbb0 fs/read_write.c:685 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f99781de019 RSP: 002b:00007f9976436028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f9978465fa0 RCX: 00007f99781de019 RDX: 0000000000000080 RSI: 0000200000000d00 RDI: 0000000000000004 RBP: 00007f997827500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9978466038 R14: 00007f9978465fa0 R15: 00007ffe7ecc1038 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff88813ff1f938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff1f938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900000f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc900000f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88807afcc280 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 4 locks held by rcuc/1/28: 1 lock held by khungtaskd/38: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by dhcpcd/5254: #0: ffffffff8f5933d8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5ee/0x7f0 net/socket.c:1383 #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xf0/0x630 net/8021q/vlan.c:519 7 locks held by kworker/u8:71/9771: 13 locks held by kworker/u8:76/9776: 6 locks held by kworker/u8:89/9789: 6 locks held by kworker/u8:174/9874: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90006317c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90006317c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5a39e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff888059dcc160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff888059dcc160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888059dcc160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff88802f6de310 (&devlink->lock_key#21){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff88802f6de310 (&devlink->lock_key#21){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff88802f6de310 (&devlink->lock_key#21){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 #5: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2103 2 locks held by getty/10002: #0: ffff8880361840a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003d232e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:5/10365: 1 lock held by syz.8.1000/10883: #0: ffffffff99bcb458 (&ls_lock){+.+.}-{4:4}, at: __dlm_new_lockspace+0xa3/0x2060 fs/dlm/lockspace.c:632 1 lock held by dlm_recoverd/10891: #0: ffff88805fde0d20 (&ls->ls_in_recovery){+.+.}-{4:4}, at: dlm_recoverd+0xba/0x23e0 fs/dlm/recoverd.c:400 2 locks held by syz-executor/11348: 1 lock held by iou-wrk-12010/12011: #0: ffffffff99bcb458 (&ls_lock){+.+.}-{4:4}, at: __dlm_new_lockspace+0xa3/0x2060 fs/dlm/lockspace.c:632 1 lock held by syz-executor/12026: #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz-executor/12096: #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7082 1 lock held by syz-executor/12137: #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7082 1 lock held by syz-executor/12160: #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9776 Comm: kworker/u8:76 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x18fa/0x2ce0 kernel/locking/lockdep.c:5237 Code: 14 25 ff 0f 00 00 39 05 70 53 04 12 73 06 89 05 68 53 04 12 48 8b 02 48 89 df 4c 39 e8 0f 84 34 fe ff ff 4c 89 78 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 20 fe ff ff 48 89 fb 48 c7 c7 f0 02 09 RSP: 0018:ffffc9000439ecb0 EFLAGS: 00000006 RAX: ffffffff965e28e8 RBX: 00000000000003cd RCX: 00000000000001a4 RDX: ffffffff96380848 RSI: ffff88802ea4ad10 RDI: 00000000000003cd RBP: 3176e83ba478c9a0 R08: ffffc9000439ec78 R09: 0000000000000020 R10: 0000000000000000 R11: ffffffff81a1d7e0 R12: 00000000000001a3 R13: ffffffff934cdbf8 R14: ffff88802ea49f00 R15: ffffffff963cbbd8 FS: 0000000000000000(0000) GS:ffff888125c3e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d669a17b0 CR3: 000000003dc2e000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 debug_object_assert_init+0xa1/0x310 lib/debugobjects.c:1070 debug_hrtimer_assert_init kernel/time/hrtimer.c:495 [inline] hrtimer_start_range_ns+0x3d/0x3f0 kernel/time/hrtimer.c:1499 hrtimer_start include/linux/hrtimer.h:223 [inline] hrtick_cond_restart kernel/sched/core.c:939 [inline] hrtick_schedule_exit kernel/sched/core.c:1001 [inline] finish_lock_switch kernel/sched/core.c:5240 [inline] finish_task_switch+0x3c4/0xc60 kernel/sched/core.c:5359 context_switch kernel/sched/core.c:5513 [inline] __schedule+0x16e4/0x5500 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 01 8a a2 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb b4 fc 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d f8 94 11 RSP: 0018:ffffc9000439f308 EFLAGS: 00000282 RAX: 04d29913c0f83500 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000575c7362 RSI: ffffffff8daf6c22 RDI: ffffffff8bca7880 RBP: ffffffff8b4673e6 R08: ffffffff8b4673e6 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8e1c3000 R12: 0000000000000002 R13: ffffffff8e1c3000 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] rt_write_lock+0xa2/0x220 kernel/locking/spinlock_rt.c:261 write_lock include/linux/rwlock_rt.h:92 [inline] neigh_remove_one+0x2d/0x4a0 net/core/neighbour.c:240 neigh_forced_gc net/core/neighbour.c:280 [inline] neigh_alloc net/core/neighbour.c:509 [inline] ___neigh_create+0x4ac/0x2390 net/core/neighbour.c:652 ip6_finish_output2+0x6d6/0x1410 net/ipv6/ip6_output.c:128 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x337/0x540 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:471 [inline] NF_HOOK+0x177/0x4f0 include/linux/netfilter.h:318 mld_sendpack+0x890/0xe10 net/ipv6/mcast.c:1869 ipv6_mc_dad_complete+0x87/0x410 net/ipv6/mcast.c:2295 addrconf_dad_completed+0x622/0xe60 net/ipv6/addrconf.c:4375 addrconf_dad_work+0xdda/0x16e0 net/ipv6/addrconf.c:-1 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245