syzbot


INFO: task hung in reg_check_chans_work (4)

Status: upstream: reported syz repro on 2025/11/18 03:08
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+49263cba201c47ac0c58@syzkaller.appspotmail.com
First crash: 53d, last: 28d
Bug presence (2)
Date Name Commit Repro Result
2025/12/12 linux-6.1.y (ToT) 50cbba13faa2 syz [report] INFO: task hung in rtnetlink_rcv_msg
2025/12/12 upstream (ToT) 187d0801404f syz Didn't crash
Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in reg_check_chans_work 1 10 429d 714d 0/3 auto-obsoleted due to no activity on 2025/02/14 20:30
linux-6.1 INFO: task hung in reg_check_chans_work (2) 1 1 385d 385d 0/3 auto-obsoleted due to no activity on 2025/03/30 18:04
upstream INFO: task hung in reg_check_chans_work (6) wireless 1 C error 129 552d 626d 26/29 fixed on 2024/07/09 19:14
upstream INFO: task hung in reg_check_chans_work (3) wireless 1 60 1497d 1560d 0/29 auto-closed as invalid on 2022/04/03 20:03
linux-4.14 INFO: task hung in reg_check_chans_work 1 1 1343d 1343d 0/1 auto-obsoleted due to no activity on 2022/09/05 08:58
upstream INFO: task hung in reg_check_chans_work (7) wireless 1 C error 822 4h12m 474d 0/29 upstream: reported C repro on 2024/09/23 08:39
upstream INFO: task hung in reg_check_chans_work (4) wireless 1 4 1289d 1292d 0/29 auto-closed as invalid on 2022/09/28 14:08
linux-6.6 INFO: task hung in reg_check_chans_work 1 5 100d 206d 0/2 auto-obsoleted due to no activity on 2026/01/10 01:05
upstream INFO: task hung in reg_check_chans_work net 1 15 2827d 2886d 0/29 closed as dup on 2018/02/14 15:33
linux-6.1 INFO: task hung in reg_check_chans_work (3) 1 1 279d 279d 0/3 auto-obsoleted due to no activity on 2025/07/15 07:58
android-44 INFO: task hung in reg_check_chans_work 1 18 2799d 2873d 0/2 auto-closed as invalid on 2019/02/22 14:50
android-49 INFO: task hung in reg_check_chans_work 1 18 2798d 2896d 0/3 auto-closed as invalid on 2019/02/22 15:19
linux-6.1 INFO: task hung in reg_check_chans_work 1 3 576d 594d 0/3 auto-obsoleted due to no activity on 2024/09/20 17:51
upstream INFO: task hung in reg_check_chans_work (5) wireless 1 26 804d 932d 0/29 auto-obsoleted due to no activity on 2024/01/08 12:17
upstream INFO: task hung in reg_check_chans_work (2) wireless 1 3 1921d 1930d 0/29 auto-closed as invalid on 2021/01/04 12:48

Sample crash report:
INFO: task kworker/0:0:7 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0     state:D stack:24040 pid:7     ppid:2      flags:0x00004000
Workqueue: events_power_efficient reg_check_chans_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
 reg_check_chans_work+0x8b/0xd80 net/wireless/reg.c:2499
 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-executor:6189 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25664 pid:6189  ppid:1      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
 ip_tunnel_init_net+0x281/0x740 net/ipv4/ip_tunnel.c:1103
 ops_init+0x355/0x5f0 net/core/net_namespace.c:138
 setup_net+0x4e1/0xbb0 net/core/net_namespace.c:336
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x4bc/0x890 kernel/fork.c:3277
 __do_sys_unshare kernel/fork.c:3348 [inline]
 __se_sys_unshare kernel/fork.c:3346 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3346
 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: 0033:0x7f38d5d90f47
RSP: 002b:00007ffd0171a308 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f38d5d90f47
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007ffd0171a350 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000002
R13: 00007ffd0171a358 R14: 00007ffd0171a5d8 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:6195 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25664 pid:6195  ppid:1      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
 register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3619
 ops_init+0x355/0x5f0 net/core/net_namespace.c:138
 setup_net+0x4e1/0xbb0 net/core/net_namespace.c:336
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x4bc/0x890 kernel/fork.c:3277
 __do_sys_unshare kernel/fork.c:3348 [inline]
 __se_sys_unshare kernel/fork.c:3346 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3346
 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: 0033:0x7f28fcf90f47
RSP: 002b:00007ffd2252f728 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f28fcf90f47
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007ffd2252f770 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 00007ffd2252f778 R14: 00007ffd2252f9f8 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:6197 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25664 pid:6197  ppid:1      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
 register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3619
 ops_init+0x355/0x5f0 net/core/net_namespace.c:138
 setup_net+0x4e1/0xbb0 net/core/net_namespace.c:336
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x4bc/0x890 kernel/fork.c:3277
 __do_sys_unshare kernel/fork.c:3348 [inline]
 __se_sys_unshare kernel/fork.c:3346 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3346
 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: 0033:0x7f977a990f47
RSP: 002b:00007ffedaaed878 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f977a990f47
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007ffedaaed8c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000002
R13: 00007ffedaaed8c8 R14: 00007ffedaaedb48 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: ffff888017471938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc900000c7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x8b/0xd80 net/wireless/reg.c:2499
4 locks held by kworker/u4:1/11:
 #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
 #3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x51/0x290 net/mac80211/main.c:1476
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c92bab0 (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: ffffffff8c92c2d0 (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/0:1/14:
1 lock held by khungtaskd/28:
 #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:2/36:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000ad7d00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/u4:3/46:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000b77d00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
4 locks held by kworker/u5:0/48:
 #0: ffff88805b139138 ((wq_completion)hci18#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000b97d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff88804bef4078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
3 locks held by kworker/u4:4/53:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000be7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
3 locks held by kworker/0:2/129:
 #0: ffff88802f379938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90002d67d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
1 lock held by dhcpcd/3931:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xd5/0xcd0 net/netlink/af_netlink.c:2179
2 locks held by getty/4029:
 #0: ffff88814dca8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
4 locks held by kworker/u5:1/4308:
 #0: ffff888078c28138 ((wq_completion)hci15#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003dc7d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff888045fbc078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
4 locks held by kworker/u5:2/4310:
 #0: ffff8880731cf938 ((wq_completion)hci13#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003df7d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff888045fb8078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
3 locks held by kworker/1:4/4350:
3 locks held by kworker/1:7/4355:
 #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004247d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
3 locks held by syz-executor/4388:
 #0: ffff8880580f90b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880580f90b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705
 #1: ffff8880580f8078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline]
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504
3 locks held by syz-executor/4392:
 #0: ffff8880580cd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880580cd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705
 #1: ffff8880580cc078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline]
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504
5 locks held by syz-executor/4396:
3 locks held by syz-executor/4400:
 #0: ffff8880594350b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880594350b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705
 #1: ffff888059434078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline]
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504
3 locks held by syz-executor/4402:
 #0: ffff88807a0050b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff88807a0050b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705
 #1: ffff88807a004078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline]
 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504
4 locks held by kworker/u5:4/4404:
 #0: ffff888073192938 ((wq_completion)hci17#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003307d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff888054db4078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
3 locks held by kworker/1:11/4475:
 #0: ffff88802f379938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003677d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
3 locks held by kworker/u4:8/4721:
 #0: ffff88801e6e9938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004407d00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_dfs_channels_update_work+0xb3/0x620 net/wireless/mlme.c:889
2 locks held by syz-executor/6182:
 #0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
 #1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3619
2 locks held by syz-executor/6189:
 #0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
 #1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x281/0x740 net/ipv4/ip_tunnel.c:1103
2 locks held by syz-executor/6195:
 #0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
 #1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3619
2 locks held by syz-executor/6197:
 #0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
 #1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3619
1 lock held by syz-executor/8060:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/8067:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/8072:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
4 locks held by kworker/u5:5/8074:
 #0: ffff888069c87138 ((wq_completion)hci12#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003697d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff88807c2f8078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
1 lock held by syz-executor/8078:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
4 locks held by kworker/u5:6/8264:
 #0: ffff88805b745138 ((wq_completion)hci16#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc9000d8afd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff888045ff8078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
4 locks held by kworker/u5:7/8265:
 #0: ffff888061b88138 ((wq_completion)hci14#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc9000dbf7d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff888045ff4078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
1 lock held by syz-executor/9960:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/9967:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/9974:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/9975:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
4 locks held by kworker/u5:8/9991:
 #0: ffff888072e92938 ((wq_completion)hci20#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc900050a7d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff88805b004078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
1 lock held by syz-executor/11731:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/11734:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/11737:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
4 locks held by kworker/u5:9/11738:
 #0: ffff88805d219938 ((wq_completion)hci19#2){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004cafd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff88802bcf8078 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x91/0xa20 net/bluetooth/hci_event.c:3763
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1811 [inline]
 #3: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x5e3/0xa20 net/bluetooth/hci_event.c:3796
1 lock held by syz-executor/11745:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4350 Comm: kworker/1:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events prog_array_map_clear_deferred
RIP: 0010:__lock_acquire+0x4a3/0x7c50 kernel/locking/lockdep.c:4989
Code: 24 b8 00 00 00 41 83 3e 00 0f 95 c0 09 c3 c1 e3 0d 8b 84 24 c0 00 00 00 c1 e0 0f 0f b7 c0 09 d8 8b 8c 24 90 00 00 00 83 e1 03 <c1> e1 10 09 c1 8b 44 24 34 83 e0 01 c1 e0 12 09 c8 8b 8c 24 d8 00
RSP: 0018:ffffc900042176c0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000892 RSI: 0000000000000000 RDI: ffff88801d26e480
RBP: ffffc90004217910 R08: dffffc0000000000 R09: 0000000000000000
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: ffff88801d26e470
R13: 0000000000000000 R14: ffff88801d26e404 R15: 0000000000000892
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93395b42f8 CR3: 000000007e446000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
 fd_array_map_delete_elem+0xe0/0x240 kernel/bpf/arraymap.c:872
 bpf_fd_array_map_clear kernel/bpf/arraymap.c:922 [inline]
 prog_array_map_clear_deferred+0x94/0x120 kernel/bpf/arraymap.c:1063
 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>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/12 11:15 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in reg_check_chans_work
2025/11/18 03:08 linux-6.1.y f6e38ae624cf ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in reg_check_chans_work
* Struck through repros no longer work on HEAD.