syzbot


INFO: task hung in linkwatch_event

Status: auto-closed as invalid on 2021/01/05 01:42
Reported-by: syzbot+4d80691aa567739e7dc1@syzkaller.appspotmail.com
First crash: 795d, last: 668d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in linkwatch_event C 7 964d 1184d 0/1 public: reported C repro on 2019/04/10 16:14
android-44 INFO: task hung in linkwatch_event 6 1400d 1545d 0/2 auto-closed as invalid on 2019/03/05 13:11
upstream INFO: task hung in linkwatch_event C 82 992d 1604d 0/22 closed as dup on 2018/02/14 15:33
linux-4.19 INFO: task hung in linkwatch_event (2) C error 159 1d04h 847d 0/1 upstream: reported C repro on 2020/03/11 20:12
upstream INFO: task hung in linkwatch_event (2) C done done 1033 73d 799d 22/22 fixed on 2022/05/13 11:13
linux-4.19 INFO: task hung in linkwatch_event 3 1001d 1115d 0/1 auto-closed as invalid on 2020/02/07 01:11
android-49 INFO: task hung in linkwatch_event 13 1163d 1180d 0/3 auto-closed as invalid on 2019/10/25 08:50

Sample crash report:
Bluetooth: hci3 command 0x0406 tx timeout
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task kworker/1:2:2750 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:2     D27224  2750      2 0x80000000
Workqueue: events linkwatch_event
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 linkwatch_event+0xa/0x50 net/core/link_watch.c:236
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task syz-executor.5:12655 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28912 12655   6364 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 unregister_netdevice_notifier+0x5e/0x2b0 net/core/dev.c:1630
 raw_release+0x53/0x7c0 net/can/raw.c:358
 __sock_release+0xcd/0x2b0 net/socket.c:602
 sock_close+0x15/0x20 net/socket.c:1139
 __fput+0x25f/0x7a0 fs/file_table.c:210
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x416f01
RSP: 002b:00007ffcbf1d4620 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416f01
RDX: 0000001b31320000 RSI: 0000000000000313 RDI: 0000000000000003
RBP: 0000000000000001 R08: 000000009fb24313 R09: 000000009fb24317
R10: 00007ffcbf1d4710 R11: 0000000000000293 R12: 000000000118d940
R13: 000000000118d940 R14: ffffffffffffffff R15: 000000000118cfec
INFO: task syz-executor.5:12659 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28552 12659   6364 0x80000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 register_netdev+0xf/0x30 net/core/dev.c:7803
 loopback_net_init+0x71/0x140 drivers/net/loopback.c:214
 ops_init+0xaa/0x3e0 net/core/net_namespace.c:118
 setup_net+0x22f/0x530 net/core/net_namespace.c:295
 copy_net_ns+0x19b/0x440 net/core/net_namespace.c:419
 create_new_namespaces+0x375/0x720 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xa1/0x1d0 kernel/nsproxy.c:206
 SYSC_unshare kernel/fork.c:2391 [inline]
 SyS_unshare+0x308/0x7f0 kernel/fork.c:2341
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007fd599119c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000036480 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000118cf70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffcbf1d45af R14: 00007fd59911a9c0 R15: 000000000118cf4c
INFO: task syz-executor.3:12668 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D26424 12668   6368 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 dev_ioctl+0x25e/0xbe0 net/core/dev_ioctl.c:421
 sock_do_ioctl net/socket.c:981 [inline]
 sock_ioctl+0x164/0x4c0 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f204cfb8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000012cc0 RCX: 000000000045d5b9
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000008
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffdcf60b4cf R14: 00007f204cfb99c0 R15: 000000000118cf4c
INFO: task syz-executor.3:12680 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D26608 12680   6368 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 exp_funnel_lock kernel/rcu/tree_exp.h:295 [inline]
 _synchronize_rcu_expedited+0x5f6/0x770 kernel/rcu/tree_exp.h:596
 synchronize_net net/core/dev.c:8239 [inline]
 netdev_rx_handler_unregister+0x6a/0xc0 net/core/dev.c:4299
 ipvlan_port_destroy+0xf1/0x3f0 drivers/net/ipvlan/ipvlan_main.c:179
 ipvlan_uninit+0xb6/0xe0 drivers/net/ipvlan/ipvlan_main.c:244
 rollback_registered_many+0x7e5/0xb30 net/core/dev.c:7216
 unregister_netdevice_many.part.0+0x18/0x2e0 net/core/dev.c:8284
 unregister_netdevice_many+0x36/0x50 net/core/dev.c:8283
 rtnl_newlink+0x13f3/0x1830 net/core/rtnetlink.c:2771
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f204cf97c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002ce80 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffdcf60b4cf R14: 00007f204cf989c0 R15: 000000000118cfec
INFO: task syz-executor.3:12753 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28800 12753   6368 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 rtnl_lock net/core/rtnetlink.c:72 [inline]
 rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f204cf55c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002ce80 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 000000000118d160 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d12c
R13: 00007ffdcf60b4cf R14: 00007f204cf569c0 R15: 000000000118d12c
INFO: task syz-executor.3:12754 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D29176 12754   6368 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 rtnl_lock net/core/rtnetlink.c:72 [inline]
 rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f204cf34c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002ce80 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000118d200 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d1cc
R13: 00007ffdcf60b4cf R14: 00007f204cf359c0 R15: 000000000118d1cc
INFO: task syz-executor.3:12755 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D30112 12755   6368 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 dev_ioctl+0x25e/0xbe0 net/core/dev_ioctl.c:421
 sock_do_ioctl net/socket.c:981 [inline]
 sock_ioctl+0x164/0x4c0 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f204cf13c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000012cc0 RCX: 000000000045d5b9
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000008
RBP: 000000000118d2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d26c
R13: 00007ffdcf60b4cf R14: 00007f204cf149c0 R15: 000000000118d26c
INFO: task syz-executor.2:12670 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28912 12670   6366 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19
 tty_release+0xa8/0xe20 drivers/tty/tty_io.c:1652
 __fput+0x25f/0x7a0 fs/file_table.c:210
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x416f01
RSP: 002b:00007ffe4929f190 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416f01
RDX: 0000000000000000 RSI: 00000000000002c8 RDI: 0000000000000004
RBP: 0000000000000001 R08: 00000000342d02c8 R09: 00000000342d02cc
R10: 00007ffe4929f280 R11: 0000000000000293 R12: 000000000118d940
R13: 000000000118d940 R14: ffffffffffffffff R15: 000000000118cfec
INFO: task syz-executor.2:12700 blocked for more than 140 seconds.
      Not tainted 4.14.196-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D30104 12700   6366 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 x25_asy_close_tty+0x90/0x1e0 drivers/net/wan/x25_asy.c:604
 tty_ldisc_close+0x8c/0xc0 drivers/tty/tty_ldisc.c:505
 tty_ldisc_kill drivers/tty/tty_ldisc.c:651 [inline]
 tty_ldisc_hangup+0x269/0x6c0 drivers/tty/tty_ldisc.c:769
 __tty_hangup.part.0+0x31a/0x730 drivers/tty/tty_io.c:622
 __tty_hangup drivers/tty/tty_io.c:572 [inline]
 tty_vhangup+0x1d/0x30 drivers/tty/tty_io.c:695
 pty_close+0x35f/0x4b0 drivers/tty/pty.c:79
 tty_release+0x402/0xe20 drivers/tty/tty_io.c:1670
 __fput+0x25f/0x7a0 fs/file_table.c:210
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f72320d3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000124
RAX: 0000000000000003 RBX: 0000000000002a00 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffe4929f11f R14: 00007f72320d49c0 R15: 000000000118cfec

Showing all locks held in the system:
1 lock held by khungtaskd/1068:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff814777f4>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
3 locks held by kworker/1:2/2750:
 #0:  ("events"){+.+.}, at: [<ffffffff813ba640>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  ((linkwatch_work).work){+.+.}, at: [<ffffffff813ba676>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (rtnl_mutex){+.+.}, at: [<ffffffff8517fbca>] linkwatch_event+0xa/0x50 net/core/link_watch.c:236
3 locks held by kworker/0:2/3347:
 #0:  ("%s"("ipv6_addrconf")){+.+.}, at: [<ffffffff813ba640>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  ((addr_chk_work).work){+.+.}, at: [<ffffffff813ba676>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (rtnl_mutex){+.+.}, at: [<ffffffff85855c2a>] addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4412
2 locks held by agetty/6074:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff8343db22>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83432e73>] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156
3 locks held by kworker/0:3/7363:
 #0:  ("events"){+.+.}, at: [<ffffffff813ba640>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  (deferred_process_work){+.+.}, at: [<ffffffff813ba676>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (rtnl_mutex){+.+.}, at: [<ffffffff864cd6da>] switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
2 locks held by syz-executor.5/12655:
 #0:  (&sb->s_type->i_mutex_key#13){+.+.}, at: [<ffffffff850b62c6>] inode_lock include/linux/fs.h:719 [inline]
 #0:  (&sb->s_type->i_mutex_key#13){+.+.}, at: [<ffffffff850b62c6>] __sock_release+0x86/0x2b0 net/socket.c:601
 #1:  (rtnl_mutex){+.+.}, at: [<ffffffff85118dbe>] unregister_netdevice_notifier+0x5e/0x2b0 net/core/dev.c:1630
2 locks held by syz-executor.5/12659:
 #0:  (net_mutex){+.+.}, at: [<ffffffff8510c276>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:410
 #1:  (rtnl_mutex){+.+.}, at: [<ffffffff851403af>] register_netdev+0xf/0x30 net/core/dev.c:7803
1 lock held by syz-executor.3/12668:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8519acde>] dev_ioctl+0x25e/0xbe0 net/core/dev_ioctl.c:421
1 lock held by syz-executor.3/12680:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311
1 lock held by syz-executor.3/12753:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311
1 lock held by syz-executor.3/12754:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311
1 lock held by syz-executor.3/12755:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8519acde>] dev_ioctl+0x25e/0xbe0 net/core/dev_ioctl.c:421
1 lock held by syz-executor.2/12670:
 #0:  (&tty->legacy_mutex/1){+.+.}, at: [<ffffffff83443faf>] tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19
4 locks held by syz-executor.2/12700:
 #0:  (&tty->legacy_mutex){+.+.}, at: [<ffffffff83443faf>] tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19
 #1:  (&tty->legacy_mutex/1){+.+.}, at: [<ffffffff83443faf>] tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19
 #2:  (&tty->ldisc_sem){++++}, at: [<ffffffff8343e64d>] __tty_ldisc_lock drivers/tty/tty_ldisc.c:332 [inline]
 #2:  (&tty->ldisc_sem){++++}, at: [<ffffffff8343e64d>] tty_ldisc_lock+0x4d/0x80 drivers/tty/tty_ldisc.c:356
 #3:  (rtnl_mutex){+.+.}, at: [<ffffffff8411c4e0>] x25_asy_close_tty+0x90/0x1e0 drivers/net/wan/x25_asy.c:604
1 lock held by systemd-udevd/12724:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8519b165>] dev_ioctl+0x6e5/0xbe0 net/core/dev_ioctl.c:490

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

NMI backtrace for cpu 1
CPU: 1 PID: 1068 Comm: khungtaskd Not tainted 4.14.196-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5b9/0xb40 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8654714e

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/09/07 01:41 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report
ci2-linux-4-14 2020/06/06 07:50 linux-4.14.y c6db52a88798 c3e9afb3 .config log report
ci2-linux-4-14 2020/06/01 19:28 linux-4.14.y 4f68020fef1c a0331e89 .config log report
ci2-linux-4-14 2020/05/11 06:53 linux-4.14.y ab9dfda23248 f8f57555 .config log report
ci2-linux-4-14 2020/05/03 08:08 linux-4.14.y 773e2b1cd56a 5457883a .config log report