INFO: task kworker/1:0:22 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:24480 pid:22    ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task syz.0.3123:16473 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3123      state:D stack:24352 pid:16473 ppid:9664   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 tun_detach drivers/net/tun.c:698 [inline]
 tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
 __fput+0x22c/0x920 fs/file_table.c:320
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 get_signal+0x11a6/0x1350 kernel/signal.c:2648
 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f90d018f749
RSP: 002b:00007ffd0ac33de8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f90d03e7da0 RCX: 00007f90d018f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f90d03e7da0 R08: 0000000000000228 R09: 0000001e0ac340df
R10: 00007f90d03e7cb0 R11: 0000000000000246 R12: 00000000000afdf4
R13: 00007f90d03e5fa0 R14: ffffffffffffffff R15: 00007ffd0ac33f00
 </TASK>
INFO: task syz.7.3031:16487 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.3031      state:D stack:25120 pid:16487 ppid:16084  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 cgrp_css_online+0x8d/0x2f0 net/core/netprio_cgroup.c:157
 online_css+0xb9/0x260 kernel/cgroup/cgroup.c:5519
 css_create kernel/cgroup/cgroup.c:5590 [inline]
 cgroup_apply_control_enable+0x804/0xb00 kernel/cgroup/cgroup.c:3282
 cgroup_mkdir+0xbe7/0xdd0 kernel/cgroup/cgroup.c:5788
 kernfs_iop_mkdir+0x24c/0x3d0 fs/kernfs/dir.c:1221
 vfs_mkdir+0x387/0x570 fs/namei.c:4114
 do_mkdirat+0x1d0/0x430 fs/namei.c:4139
 __do_sys_mkdirat fs/namei.c:4154 [inline]
 __se_sys_mkdirat fs/namei.c:4152 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f969bd8f749
RSP: 002b:00007f969cc60038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f969bfe5fa0 RCX: 00007f969bd8f749
RDX: 00000000000001ff RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f969be13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f969bfe6038 R14: 00007f969bfe5fa0 R15: 00007ffd5e826248
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
3 locks held by kworker/1:0/22:
 #0: ffff88802f57a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc900001c7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
1 lock held by khungtaskd/28:
 #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
1 lock held by klogd/3626:
2 locks held by getty/4029:
 #0: ffff8880300dc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
4 locks held by syz-executor/4255:
1 lock held by syz-executor/9664:
2 locks held by syz-executor/9665:
4 locks held by kworker/u4:48/10717:
 #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003d27d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
 #3: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x18/0x1c0 drivers/net/wireguard/device.c:421
3 locks held by kworker/0:9/10993:
 #0: ffff88802f57a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004037d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4672
3 locks held by kworker/1:5/16288:
 #0: ffff888017471938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003a77d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x8b/0xd80 net/wireless/reg.c:2499
1 lock held by syz.0.3123/16473:
 #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
 #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
2 locks held by syz.0.3123/16485:
4 locks held by syz.7.3031/16487:
 #0: ffff8880736d8460 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
 #1: ffff8880724b9aa0 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
 #1: ffff8880724b9aa0 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3884
 #2: ffffffff8cb536e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
 #2: ffffffff8cb536e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1700
 #3: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: cgrp_css_online+0x8d/0x2f0 net/core/netprio_cgroup.c:157

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xeee/0xf30 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 16087 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lock_acquire+0x218/0x490 kernel/locking/lockdep.c:5666
Code: f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 <66> 43 c7 44 3d 09 00 00 43 c6 44 3d 0b 00 65 48 8b 04 25 28 00 00
RSP: 0018:ffffc90005857940 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: e064cb5b1424ee00
RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef760
RBP: ffffc90005857a48 R08: dffffc0000000000 R09: fffffbfff215c44b
R10: fffffbfff215c44b R11: 1ffffffff215c44a R12: 0000000000000000
R13: 1ffff92000b0af34 R14: 0000000000000046 R15: dffffc0000000000
FS:  0000555563301500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f90cd7cef00 CR3: 000000005948a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
 spin_lock_irq include/linux/spinlock.h:376 [inline]
 __set_current_blocked+0xe7/0x240 kernel/signal.c:3058
 set_current_blocked kernel/signal.c:3044 [inline]
 signal_delivered kernel/signal.c:2907 [inline]
 signal_setup_done+0x28c/0x440 kernel/signal.c:2919
 handle_signal arch/x86/kernel/signal.c:846 [inline]
 arch_do_signal_or_restart+0xecc/0x1240 arch/x86/kernel/signal.c:873
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc4fe64d6e0
Code: 44 24 20 0f 29 44 24 30 0f 29 44 24 40 48 8b 44 24 08 ff d0 48 83 c4 50 31 c0 5b 5d 41 5c 41 5d 41 5e c3 0f 1f 80 00 00 00 00 <c3> 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 c3 66 66 2e 0f 1f
RSP: 002b:00007ffd00caa2f8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000023 RCX: 00007fc4fe785897
RDX: 00007ffd00caa300 RSI: 00007ffd00caa430 RDI: 0000000000000011
RBP: 00007ffd00caa91c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 00000000000ab103 R15: 00007ffd00caa970
 </TASK>