INFO: task kworker/u4:6:3694 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D26416 3694 2 0x80000000 Workqueue: netns cleanup_net Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 ip6_tnl_exit_net+0x77/0x580 net/ipv6/ip6_tunnel.c:2254 ops_exit_list.isra.3+0xa8/0x150 net/core/net_namespace.c:142 cleanup_net+0x3e9/0x880 net/core/net_namespace.c:483 process_one_work+0x86e/0x15c0 kernel/workqueue.c:2114 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248 kthread+0x348/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 INFO: task syz-executor1:15396 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D27624 15396 1839 0x80000002 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 raw_close+0xe/0x30 net/ipv4/raw.c:699 inet_release+0xf7/0x1c0 net/ipv4/af_inet.c:444 __sock_release+0xce/0x250 net/socket.c:602 sock_close+0x15/0x20 net/socket.c:1138 __fput+0x25e/0x6f0 fs/file_table.c:210 task_work_run+0x116/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x8f8/0x2800 kernel/exit.c:865 do_group_exit+0x100/0x2e0 kernel/exit.c:968 get_signal+0x4e5/0x1470 kernel/signal.c:2348 do_signal+0x8f/0x1660 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x116/0x150 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x35d/0x4b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457679 RSP: 002b:00007fa323c6ecf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072bf08 RCX: 0000000000457679 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c R13: 00007ffca169fb7f R14: 00007fa323c6f9c0 R15: 0000000000000000 INFO: task syz-executor4:28692 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D26728 28692 6587 0x80000006 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 netdev_run_todo+0x20c/0x750 net/core/dev.c:7872 tun_detach drivers/net/tun.c:587 [inline] tun_chr_close+0x45/0x50 drivers/net/tun.c:2655 __fput+0x25e/0x6f0 fs/file_table.c:210 task_work_run+0x116/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x8f8/0x2800 kernel/exit.c:865 do_group_exit+0x100/0x2e0 kernel/exit.c:968 get_signal+0x4e5/0x1470 kernel/signal.c:2348 do_signal+0x8f/0x1660 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x116/0x150 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x35d/0x4b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4574e7 RSP: 002b:00007f0d58015a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffff7 RBX: 0000000020000090 RCX: 00000000004574e7 RDX: 0000000000000005 RSI: 0000000000004c00 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000000 R14: 00000000004c4a2c R15: 0000000000000001 INFO: task syz-executor1:28715 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D25000 28715 1839 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 netdev_wait_allrefs net/core/dev.c:7791 [inline] netdev_run_todo+0x31f/0x750 net/core/dev.c:7885 rtnl_unlock net/core/rtnetlink.c:106 [inline] rtnetlink_rcv_msg+0x3c8/0xb30 net/core/rtnetlink.c:4257 netlink_rcv_skb+0x130/0x390 net/netlink/af_netlink.c:2432 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline] netlink_unicast+0x46d/0x620 net/netlink/af_netlink.c:1312 netlink_sendmsg+0x664/0xbe0 net/netlink/af_netlink.c:1877 sock_sendmsg_nosec net/socket.c:645 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:655 ___sys_sendmsg+0x741/0x890 net/socket.c:2061 __sys_sendmsg+0xca/0x170 net/socket.c:2095 SYSC_sendmsg net/socket.c:2106 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2102 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457679 RSP: 002b:00007fa323c6ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa323c6f6d4 RCX: 0000000000457679 RDX: 0000000000000800 RSI: 0000000020000080 RDI: 0000000000000007 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d5538 R14: 00000000004c38e7 R15: 0000000000000000 INFO: task syz-executor1:28722 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D25368 28722 1839 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 netdev_run_todo+0x20c/0x750 net/core/dev.c:7872 rtnl_unlock net/core/rtnetlink.c:106 [inline] rtnetlink_rcv_msg+0x3c8/0xb30 net/core/rtnetlink.c:4257 netlink_rcv_skb+0x130/0x390 net/netlink/af_netlink.c:2432 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline] netlink_unicast+0x46d/0x620 net/netlink/af_netlink.c:1312 netlink_sendmsg+0x664/0xbe0 net/netlink/af_netlink.c:1877 sock_sendmsg_nosec net/socket.c:645 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:655 ___sys_sendmsg+0x741/0x890 net/socket.c:2061 __sys_sendmsg+0xca/0x170 net/socket.c:2095 SYSC_sendmsg net/socket.c:2106 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2102 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457679 RSP: 002b:00007fa323beac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa323beb6d4 RCX: 0000000000457679 RDX: 0000000000000800 RSI: 0000000020000080 RDI: 0000000000000007 RBP: 000000000072c180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d5538 R14: 00000000004c38e7 R15: 0000000000000004 INFO: task kworker/0:6:28732 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:6 D29912 28732 2 0x80000000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 addrconf_dad_work+0xa2/0x1100 net/ipv6/addrconf.c:3935 process_one_work+0x86e/0x15c0 kernel/workqueue.c:2114 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248 kthread+0x348/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 INFO: task kworker/0:12:28739 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:12 D29976 28739 2 0x80000000 Workqueue: events linkwatch_event Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 linkwatch_event+0xa/0x50 net/core/link_watch.c:236 process_one_work+0x86e/0x15c0 kernel/workqueue.c:2114 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248 kthread+0x348/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541 2 locks held by getty/1753: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1ff/0x15e0 drivers/tty/n_tty.c:2142 4 locks held by kworker/u4:6/3694: #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x14c/0x880 net/core/net_namespace.c:449 #3: (rtnl_mutex){+.+.}, at: [] ip6_tnl_exit_net+0x77/0x580 net/ipv6/ip6_tunnel.c:2254 3 locks held by kworker/1:4/4854: #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085 #1: ((addr_chk_work).work){+.+.}, at: [] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089 #2: (rtnl_mutex){+.+.}, at: [] addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4432 2 locks held by syz-executor1/15396: #0: (&sb->s_type->i_mutex_key#9){+.+.}, at: [] inode_lock include/linux/fs.h:713 [inline] #0: (&sb->s_type->i_mutex_key#9){+.+.}, at: [] __sock_release+0x84/0x250 net/socket.c:601 #1: (rtnl_mutex){+.+.}, at: [] raw_close+0xe/0x30 net/ipv4/raw.c:699 1 lock held by syz-executor4/28692: #0: (rtnl_mutex){+.+.}, at: [] netdev_run_todo+0x20c/0x750 net/core/dev.c:7872 1 lock held by syz-executor1/28715: #0: (rtnl_mutex){+.+.}, at: [] netdev_wait_allrefs net/core/dev.c:7791 [inline] #0: (rtnl_mutex){+.+.}, at: [] netdev_run_todo+0x31f/0x750 net/core/dev.c:7885 1 lock held by syz-executor1/28722: #0: (rtnl_mutex){+.+.}, at: [] netdev_run_todo+0x20c/0x750 net/core/dev.c:7872 3 locks held by kworker/0:6/28732: #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085 #1: ((&(&ifa->dad_work)->work)){+.+.}, at: [] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089 #2: (rtnl_mutex){+.+.}, at: [] addrconf_dad_work+0xa2/0x1100 net/ipv6/addrconf.c:3935 3 locks held by kworker/0:12/28739: #0: ("events"){+.+.}, at: [] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085 #1: ((linkwatch_work).work){+.+.}, at: [] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089 #2: (rtnl_mutex){+.+.}, at: [] linkwatch_event+0xa/0x50 net/core/link_watch.c:236 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.71+ #8 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 nmi_cpu_backtrace.cold.0+0x47/0x85 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x574/0xa70 kernel/hung_task.c:252 kthread+0x348/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 28627 Comm: syz-executor5 Not tainted 4.14.71+ #8 task: ffff8801a34b5e00 task.stack: ffff8801c6c38000 RIP: 0033:0x40157b RSP: 002b:00007fb3ea3c7690 EFLAGS: 00000202 RAX: 0000000057e3c2d5 RBX: 0000000000000007 RCX: 0000000000457679 RDX: 0000000000000000 RSI: 00007fb3ea3c76c0 RDI: 0000000000000007 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d7950 R14: 00000000004c48c6 R15: 0000000000000000 FS: 00007fb3ea3c8700(0000) GS:ffff8801dba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000199b680 CR3: 00000001d6a2a002 CR4: 00000000001606b0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600