syzbot


INFO: task hung in nl80211_pre_doit

Status: upstream: reported on 2026/02/12 18:12
Reported-by: syzbot+8289f9611e8b78a91b2c@syzkaller.appspotmail.com
First crash: 14d, last: 14d
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in rtnetlink_rcv_msg net 1 C inconclusive inconclusive 1970 598d 2561d 26/29 fixed on 2024/07/09 19:14
upstream INFO: task hung in nl80211_pre_doit (3) wireless 1 syz error error 32 88d 470d 0/29 upstream: reported syz repro on 2024/11/14 08:18
upstream INFO: task hung in nl80211_pre_doit wireless 1 5 1848d 1925d 0/29 auto-closed as invalid on 2021/05/17 09:21
linux-4.19 INFO: task hung in nl80211_pre_doit 1 1 1506d 1506d 0/1 auto-closed as invalid on 2022/05/13 08:55
upstream INFO: task hung in nl80211_pre_doit (2) wireless 1 18 1592d 1632d 0/29 auto-closed as invalid on 2022/01/17 00:54
linux-5.15 INFO: task hung in nl80211_pre_doit 1 9 603d 643d 0/3 auto-obsoleted due to no activity on 2024/10/11 11:32
linux-5.15 INFO: task hung in nl80211_pre_doit (2) 1 2 472d 490d 0/3 auto-obsoleted due to no activity on 2025/02/19 14:46
linux-4.19 INFO: task hung in nl80211_pre_doit (2) 1 1 1154d 1154d 0/1 upstream: reported on 2022/12/31 06:52
linux-6.1 INFO: task hung in nl80211_pre_doit 1 7 616d 644d 0/3 auto-obsoleted due to no activity on 2024/09/28 20:22

Sample crash report:
INFO: task dhcpcd:5430 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:25000 pid:5430  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:16515
 genl_family_rcv_msg_doit+0x1c8/0x310 net/netlink/genetlink.c:966
 genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
 genl_rcv_msg+0x619/0x7a0 net/netlink/genetlink.c:1066
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0788a16407
RSP: 002b:00007ffcc96f7e60 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f078898c740 RCX: 00007f0788a16407
RDX: 0000000000000000 RSI: 00007ffcc96f7ee0 RDI: 000000000000000e
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 000000000000000e R14: 00007ffcc96fc9e0 R15: 000055df886bed80
 </TASK>
INFO: task kworker/u4:12:6702 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:12   state:D stack:19784 pid:6702  ppid:2      flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 linkwatch_event+0xe/0x60 net/core/link_watch.c:286
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task kworker/u4:20:6724 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:20   state:D stack:21576 pid:6724  ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4718
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task kworker/u4:21:6729 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:21   state:D stack:19976 pid:6729  ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 wg_destruct+0x25/0x310 drivers/net/wireguard/device.c:247
 netdev_run_todo+0xbf1/0xdc0 net/core/dev.c:10606
 default_device_exit_batch+0x9f3/0xa80 net/core/dev.c:11634
 ops_exit_list net/core/net_namespace.c:178 [inline]
 cleanup_net+0x795/0xbb0 net/core/net_namespace.c:652
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz.8.5514:25366 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.5514      state:D stack:27656 pid:25366 ppid:24834  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 dev_ethtool+0x1e2/0x18d0 net/ethtool/ioctl.c:3111
 dev_ioctl+0x392/0x1140 net/core/dev_ioctl.c:708
 sock_do_ioctl+0x239/0x310 net/socket.c:1233
 sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8e3799bf79
RSP: 002b:00007f8e387b1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8e37c16090 RCX: 00007f8e3799bf79
RDX: 0000200000000080 RSI: 0000000000008946 RDI: 000000000000004a
RBP: 00007f8e37a327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8e37c16128 R14: 00007f8e37c16090 R15: 00007ffd0f5b66e8
 </TASK>
INFO: task syz.6.5524:25368 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.5524      state:D stack:28968 pid:25368 ppid:24645  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 dev_ioctl+0x7a4/0x1140 net/core/dev_ioctl.c:769
 sock_do_ioctl+0x239/0x310 net/socket.c:1233
 sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f55c299bf79
RSP: 002b:00007f55c0bf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f55c2c16090 RCX: 00007f55c299bf79
RDX: 0000200000000040 RSI: 0000000000008914 RDI: 0000000000000008
RBP: 00007f55c2a327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55c2c16128 R14: 00007f55c2c16090 R15: 00007fffc7b89128
 </TASK>
INFO: task syz.4.5513:25364 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.5513      state:D stack:24168 pid:25364 ppid:24177  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 bpf_xdp_link_attach+0x136/0x730 net/core/dev.c:9593
 link_create+0x3ff/0x720 kernel/bpf/syscall.c:5081
 __sys_bpf+0x4d7/0x890 kernel/bpf/syscall.c:5546
 __do_sys_bpf kernel/bpf/syscall.c:5580 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5578 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5578
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2bf3b9bf79
RSP: 002b:00007f2bf1df6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f2bf3e15fa0 RCX: 00007f2bf3b9bf79
RDX: 0000000000000040 RSI: 0000200000000240 RDI: 000000000000001c
RBP: 00007f2bf3c327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2bf3e16038 R14: 00007f2bf3e15fa0 R15: 00007ffd5bd4e168
 </TASK>
INFO: task syz.4.5513:25370 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.5513      state:D stack:26856 pid:25370 ppid:24177  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:78 [inline]
 rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2bf3b9bf79
RSP: 002b:00007f2bf1dd5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2bf3e16090 RCX: 00007f2bf3b9bf79
RDX: 0000000000000000 RSI: 0000200000000600 RDI: 0000000000000007
RBP: 00007f2bf3c327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2bf3e16128 R14: 00007f2bf3e16090 R15: 00007ffd5bd4e168
 </TASK>
INFO: task syz.5.5519:25375 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.5519      state:D stack:24232 pid:25375 ppid:25033  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 ip_rt_ioctl+0x115/0x11b0 net/ipv4/fib_frontend.c:630
 inet_ioctl+0x49e/0x560 net/ipv4/af_inet.c:970
 sock_do_ioctl+0xfc/0x310 net/socket.c:1219
 sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fedb239bf79
RSP: 002b:00007fedb31b0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fedb2615fa0 RCX: 00007fedb239bf79
RDX: 0000200000000100 RSI: 000000000000890b RDI: 0000000000000007
RBP: 00007fedb24327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fedb2616038 R14: 00007fedb2615fa0 R15: 00007ffdcb5126c8
 </TASK>
INFO: task syz.5.5519:25376 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.5519      state:D stack:28264 pid:25376 ppid:25033  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 ip_rt_ioctl+0x115/0x11b0 net/ipv4/fib_frontend.c:630
 inet_ioctl+0x49e/0x560 net/ipv4/af_inet.c:970
 sock_do_ioctl+0xfc/0x310 net/socket.c:1219
 sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fedb239bf79
RSP: 002b:00007fedb318f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fedb2616090 RCX: 00007fedb239bf79
RDX: 0000200000000100 RSI: 000000000000890c RDI: 0000000000000007
RBP: 00007fedb24327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fedb2616128 R14: 00007fedb2616090 R15: 00007ffdcb5126c8
 </TASK>
Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by dhcpcd/5430:
 #0: ffffffff8e424cf0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1074
 #1: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:16515
2 locks held by getty/5524:
 #0: ffff88802d8640a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
3 locks held by kworker/u4:12/6702:
 #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #1: ffffc90003517d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90003517d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #2: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
3 locks held by kworker/u4:20/6724:
 #0: ffff88802c4a5938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff88802c4a5938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #1: ffffc90003647d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90003647d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #2: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4718
4 locks held by kworker/u4:21/6729:
 #0: ffff888017c73938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017c73938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #1: ffffc90003437d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90003437d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #2: ffffffff8e3b31d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606
 #3: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: wg_destruct+0x25/0x310 drivers/net/wireguard/device.c:247
3 locks held by kworker/1:10/21215:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #1: ffffc90019167d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90019167d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #2: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz.4.5395/24464:
3 locks held by kworker/1:0/24898:
 #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #1: ffffc900037d7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900037d7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
 #2: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x92/0xd90 net/wireless/reg.c:2463
2 locks held by kworker/u4:4/25356:
1 lock held by syz.8.5514/25366:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: dev_ethtool+0x1e2/0x18d0 net/ethtool/ioctl.c:3111
1 lock held by syz.6.5524/25368:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x7a4/0x1140 net/core/dev_ioctl.c:769
1 lock held by syz.4.5513/25364:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: bpf_xdp_link_attach+0x136/0x730 net/core/dev.c:9593
1 lock held by syz.4.5513/25370:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz.5.5519/25375:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: ip_rt_ioctl+0x115/0x11b0 net/ipv4/fib_frontend.c:630
1 lock held by syz.5.5519/25376:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: ip_rt_ioctl+0x115/0x11b0 net/ipv4/fib_frontend.c:630
4 locks held by syz.5.5519/25377:
 #0: ffff888078566418 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88805cd855a0 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff88805cd855a0 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: filename_create+0x20c/0x480 fs/namei.c:3890
 #2: ffffffff8d15ba08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline]
 #2: ffffffff8d15ba08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xf2/0x230 kernel/cgroup/cgroup.c:1677
 #3: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: cgrp_css_online+0x91/0x2f0 net/core/netprio_cgroup.c:157
1 lock held by syz.5.5519/25378:
 #0: ffff88805cd855a0 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:814 [inline]
 #0: ffff88805cd855a0 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1718
1 lock held by syz-executor/25384:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25387:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25389:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25393:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25400:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25403:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25406:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25409:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25414:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25421:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25423:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469
1 lock held by syz-executor/25426:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf3d/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7039 Comm: kworker/u4:23 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:lock_is_held_type+0x50/0x190 kernel/locking/lockdep.c:5818
Code: 3d 40 b3 06 04 00 0f 84 03 01 00 00 65 8b 05 af 2a 7e 75 85 c0 0f 85 f4 00 00 00 65 48 8b 1d 77 56 7f 75 83 bb dc 0a 00 00 00 <0f> 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f
RSP: 0018:ffffc9000bbb7298 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88802786bc00 RCX: 0000000000000000
RDX: ffff88802786bc00 RSI: 00000000ffffffff RDI: ffff88807b558168
RBP: 00000000ffffffff R08: 0000000000000000 R09: 1ffff1100d66f018
R10: dffffc0000000000 R11: ffffed100d66f019 R12: ffffc9000bbb7548
R13: ffff88807b558168 R14: ffff88807b5581a8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005595d4e6c000 CR3: 000000000cf32000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 lock_is_held include/linux/lockdep.h:288 [inline]
 bss_ref_get net/wireless/scan.c:145 [inline]
 __cfg80211_bss_update+0x102c/0x21f0 net/wireless/scan.c:1949
 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2982 [inline]
 cfg80211_inform_bss_frame_data+0xb42/0x13d0 net/wireless/scan.c:3013
 ieee80211_bss_info_update+0x759/0x9b0 net/mac80211/scan.c:211
 ieee80211_rx_bss_info net/mac80211/ibss.c:1124 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1613 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x18ae/0x2c80 net/mac80211/ibss.c:1642
 ieee80211_iface_process_skb net/mac80211/iface.c:1655 [inline]
 ieee80211_iface_work+0x717/0xc70 net/mac80211/iface.c:1709
 cfg80211_wiphy_work+0x225/0x260 net/wireless/core.c:437
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/12 18:11 linux-6.6.y 1b4ef5214f17 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in nl80211_pre_doit
* Struck through repros no longer work on HEAD.