syzbot


INFO: task hung in unregister_nexthop_notifier (5)

Status: auto-obsoleted due to no activity on 2026/01/08 04:28
Subsystems: net
[Documentation on labels]
First crash: 61d, last: 61d
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in unregister_nexthop_notifier (3) net 1 7 416d 469d 0/29 auto-obsoleted due to no activity on 2025/02/17 23:47
upstream INFO: task hung in unregister_nexthop_notifier (2) net 1 15 543d 598d 0/29 auto-obsoleted due to no activity on 2024/09/07 21:36
upstream INFO: task hung in unregister_nexthop_notifier (4) net 1 1 319d 319d 0/29 auto-obsoleted due to no activity on 2025/05/25 05:10
linux-5.15 INFO: task hung in unregister_nexthop_notifier 1 1 588d 588d 0/3 auto-obsoleted due to no activity on 2024/09/08 17:20
upstream INFO: task hung in unregister_nexthop_notifier net 1 1 920d 920d 0/29 auto-obsoleted due to no activity on 2023/10/02 08:35

Sample crash report:
INFO: task kworker/u8:0:12 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:21408 pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3999
 nsim_fib_destroy+0x89/0x180 drivers/net/netdevsim/fib.c:1657
 nsim_dev_reload_destroy+0x2e3/0x490 drivers/net/netdevsim/dev.c:1711
 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:983
 devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461
 devlink_pernet_pre_exit+0x1d9/0x3d0 net/devlink/core.c:509
 ops_pre_exit_list net/core/net_namespace.c:161 [inline]
 ops_undo_list+0x187/0x990 net/core/net_namespace.c:234
 cleanup_net+0x4d8/0x880 net/core/net_namespace.c:696
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task kworker/u8:8:4534 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8    state:D stack:21576 pid:4534  tgid:4534  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 linkwatch_event+0xe/0x60 net/core/link_watch.c:303
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task dhcpcd:5489 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:24744 pid:5489  tgid:5489  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:579
 sock_ioctl+0x610/0x790 net/socket.c:1343
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5398043378
RSP: 002b:00007ffe4cd0cf78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000055a640149340 RCX: 00007f5398043378
RDX: 00007ffe4cd0cf80 RSI: 0000000000008982 RDI: 000000000000000f
RBP: 00007ffe4cd0cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000055a640146850 R14: 00007ffe4cd0d9d0 R15: 000055a640149340
 </TASK>
INFO: task kworker/0:6:5958 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6     state:D stack:22424 pid:5958  tgid:5958  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task kworker/u8:9:6028 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:22344 pid:6028  tgid:6028  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 udp_tunnel_nic_device_sync_work+0x29/0xa50 net/ipv4/udp_tunnel_nic.c:736
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task kworker/u8:12:6887 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:12   state:D stack:22280 pid:6887  tgid:6887  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor:7980 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:21768 pid:7980  tgid:7980  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1120
 inet_ioctl+0x3c0/0x4c0 net/ipv4/af_inet.c:1024
 sock_do_ioctl+0xdc/0x300 net/socket.c:1258
 sock_ioctl+0x576/0x790 net/socket.c:1379
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc1af8f2cb
RSP: 002b:00007fff6c8ad710 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fff6c8ad830 RCX: 00007efc1af8f2cb
RDX: 00007fff6c8ad790 RSI: 0000000000008914 RDI: 0000000000000005
RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000025
R13: 0000000000000048 R14: 00007efc1bd14620 R15: 00007fff6c8ad790
 </TASK>
INFO: task syz-executor:8045 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21672 pid:8045  tgid:8045  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_lock net/core/rtnetlink.c:80 [inline]
 rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:746
 __sys_sendto+0x3bd/0x520 net/socket.c:2248
 __do_sys_sendto net/socket.c:2255 [inline]
 __se_sys_sendto net/socket.c:2251 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2251
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8fd199155c
RSP: 002b:00007fffa3790190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f8fd2714620 RCX: 00007f8fd199155c
RDX: 0000000000000020 RSI: 00007f8fd2714670 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007fffa37901e4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005
R13: 00007fffa379024c R14: 00007f8fd2714670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:8184 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22568 pid:8184  tgid:8184  ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_lock net/core/rtnetlink.c:80 [inline]
 rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:746
 __sys_sendto+0x3bd/0x520 net/socket.c:2248
 __do_sys_sendto net/socket.c:2255 [inline]
 __se_sys_sendto net/socket.c:2251 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2251
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe32f99155c
RSP: 002b:00007ffe7ba54520 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe330714620 RCX: 00007fe32f99155c
RDX: 000000000000003c RSI: 00007fe330714670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe7ba54574 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fe330714670 R15: 0000000000000000
 </TASK>
INFO: task syz.2.424:8232 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.424       state:D stack:28296 pid:8232  tgid:8230  ppid:7972   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 ppp_ioctl+0xcd/0x19a0 drivers/net/ppp/ppp_generic.c:734
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9e9738f6c9
RSP: 002b:00007f9e981f7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9e975e6090 RCX: 00007f9e9738f6c9
RDX: 0000200000000100 RSI: 0000000040107447 RDI: 0000000000000004
RBP: 00007f9e97411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9e975e6128 R14: 00007f9e975e6090 R15: 00007ffe893de8d8
 </TASK>
Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings
INFO: task syz-executor:8246 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22568 pid:8246  tgid:8246  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
 __schedule_loop kernel/sched/core.c:6954 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6969
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_lock net/core/rtnetlink.c:80 [inline]
 rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:746
 __sys_sendto+0x3bd/0x520 net/socket.c:2248
 __do_sys_sendto net/socket.c:2255 [inline]
 __se_sys_sendto net/socket.c:2251 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2251
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c5059155c
RSP: 002b:00007ffdc7ea24a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f9c51314620 RCX: 00007f9c5059155c
RDX: 0000000000000050 RSI: 00007f9c51314670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffdc7ea24f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f9c51314670 R15: 0000000000000000
 </TASK>
Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings

Showing all locks held in the system:
6 locks held by kworker/u8:0/12:
 #0: ffff88801b29f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
 #1: ffffc90000117b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
 #2: ffffffff8f2ca890 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x880 net/core/net_namespace.c:670
 #3: ffff888051f6c0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #3: ffff888051f6c0e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
 #3: ffff888051f6c0e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506
 #4: ffff888051f6d250 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
 #4: ffff888051f6d250 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
 #4: ffff888051f6d250 (&devlink->lock_key#12){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506
 #5: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3999
1 lock held by khungtaskd/31:
 #0: ffffffff8df3b720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3b720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3b720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:8/4534:
 #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
 #1: ffffc9000d527b80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
 #2: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by dhcpcd/5489:
 #0: ffffffff8f2bbba8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5ee/0x790 net/socket.c:1341
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:579
2 locks held by getty/5586:
 #0: ffff88803074b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036be2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:6/5958:
 #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
 #1: ffffc90004a17b80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
 #2: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
3 locks held by kworker/u8:9/6028:
 #0: ffff88814d731148 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
 #1: ffffc90004b9fb80 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
 #2: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work+0x29/0xa50 net/ipv4/udp_tunnel_nic.c:736
3 locks held by kworker/u8:12/6887:
 #0: ffff88802f63d948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
 #1: ffffc9001ae57b80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
 #2: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
5 locks held by syz.2.368/7517:
1 lock held by syz-executor/7980:
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1120
1 lock held by syz-executor/8045:
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964
2 locks held by syz-executor/8184:
 #0: ffffffff8ea752a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ea752a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8ea752a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
2 locks held by syz.2.424/8231:
1 lock held by syz.2.424/8232:
 #0: ffffffff8eab7be8 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xcd/0x19a0 drivers/net/ppp/ppp_generic.c:734
2 locks held by syz-executor/8246:
 #0: ffffffff8f7deb60 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8f7deb60 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8f7deb60 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
7 locks held by syz-executor/8267:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff88805f994c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
 #4: ffff8880317640e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #4: ffff8880317640e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
 #4: ffff8880317640e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
 #5: ffff888031765250 (&devlink->lock_key#15){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
 #6: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11559 [inline]
 #6: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x70f/0x10c0 net/core/dev.c:11684
2 locks held by syz-executor/8272:
 #0: ffffffff8f2ca890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x560 net/core/net_namespace.c:577
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3971
4 locks held by syz-executor/8320:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff8880564e0488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
1 lock held by syz-executor/8330:
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
4 locks held by syz-executor/8334:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff88807d09dc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/8348:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff888056572c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
1 lock held by syz-executor/8359:
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
4 locks held by syz-executor/8363:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff888055725088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
2 locks held by syz-executor/8373:
 #0: ffffffff8f2ca890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x560 net/core/net_namespace.c:577
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #1: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2084
4 locks held by syz-executor/8376:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff888038b74888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/8389:
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2703 [inline]
 #0: ffff888033a78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #1: ffff888064edf088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8880274671e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8eb6e568 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
1 lock held by syz-executor/8395:
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f2d7e08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:336 [inline]
 watchdog+0xfa9/0xff0 kernel/hung_task.c:499
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 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: 7517 Comm: syz.2.368 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:check_preemption_disabled+0x6/0x120 lib/smp_processor_id.c:13
Code: c7 c6 c0 41 bf 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 <48> 83 ec 10 65 48 8b 05 fe 91 19 07 48 89 44 24 08 65 8b 05 06 92
RSP: 0018:ffffc9000b6379f8 EFLAGS: 00000046
RAX: ffff88802680db80 RBX: 0000000000000000 RCX: 0b886c8932228e00
RDX: 0000000000000000 RSI: ffffffff8d79afb1 RDI: ffffffff8bbf41e0
RBP: ffffffff8241d576 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100a9f708b R12: 0000000000000000
R13: ffffffff8dc148d8 R14: 0000000000000001 R15: 0000000000000246
FS:  00007f0e343e46c0(0000) GS:ffff888125fc2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563ee8d30f40 CR3: 000000007b0dc000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
 lock_acquire+0xe7/0x360 kernel/locking/lockdep.c:5867
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 insert_inode_locked+0x336/0x5d0 fs/inode.c:1837
 ntfs_new_inode+0xc8/0x100 fs/ntfs3/fsntfs.c:1688
 ntfs_create_inode+0x606/0x32a0 fs/ntfs3/inode.c:1309
 ntfs_mkdir+0x3d/0x50 fs/ntfs3/namei.c:215
 vfs_mkdir+0x360/0x580 fs/namei.c:4453
 do_mkdirat+0x28a/0x650 fs/namei.c:4486
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e3358de17
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0e343e3e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0e343e3ef0 RCX: 00007f0e3358de17
RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007f0e343e3eb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/09 04:28 linux-next 9c0826a5d9aa 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in unregister_nexthop_notifier
* Struck through repros no longer work on HEAD.