INFO: task kworker/u4:6:8204 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D18584 8204 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline] _synchronize_rcu_expedited.constprop.0+0x7fa/0x8d0 kernel/rcu/tree_exp.h:622 synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:762 synchronize_net+0x3b/0x60 net/core/dev.c:9162 tipc_nametbl_stop+0x947/0xc90 net/tipc/name_table.c:797 tipc_exit_net+0x2e/0x40 net/tipc/core.c:103 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153 cleanup_net+0x51d/0xb10 net/core/net_namespace.c:551 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task syz-executor0:26924 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D25408 26924 7995 0x80000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 cangw_pernet_exit+0x13/0x30 net/can/gw.c:1029 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x4b2/0x8c0 net/core/net_namespace.c:331 copy_net_ns+0x2ae/0x4b0 net/core/net_namespace.c:437 create_new_namespaces+0x4ce/0x930 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x6d7/0xfb0 kernel/fork.c:2545 __do_sys_unshare kernel/fork.c:2613 [inline] __se_sys_unshare kernel/fork.c:2611 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2611 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f1089ed7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000048000000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1089ed86d4 R13: 00000000004c6ac9 R14: 00000000004dbe18 R15: 00000000ffffffff INFO: task syz-executor0:26938 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D25880 26938 7995 0x80000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 cangw_pernet_exit+0x13/0x30 net/can/gw.c:1029 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x4b2/0x8c0 net/core/net_namespace.c:331 copy_net_ns+0x2ae/0x4b0 net/core/net_namespace.c:437 create_new_namespaces+0x4ce/0x930 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x6d7/0xfb0 kernel/fork.c:2545 __do_sys_unshare kernel/fork.c:2613 [inline] __se_sys_unshare kernel/fork.c:2611 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2611 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f1089e74c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000048000000 RBP: 000000000073c180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1089e756d4 R13: 00000000004c6ac9 R14: 00000000004dbe18 R15: 00000000ffffffff INFO: task syz-executor2:26949 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D26808 26949 30515 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 dev_ioctl+0x1aa/0xc70 net/core/dev_ioctl.c:487 sock_do_ioctl+0x1d9/0x400 net/socket.c:973 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f4edb361c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000020000040 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4edb3626d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff INFO: task syz-executor2:26954 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D26808 26954 30515 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 dev_ioctl+0x1aa/0xc70 net/core/dev_ioctl.c:487 sock_do_ioctl+0x1d9/0x400 net/socket.c:973 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f4edb340c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 00000000200001c0 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4edb3416d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff INFO: task syz-executor2:26978 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D26808 26978 30515 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 dev_ioctl+0x1aa/0xc70 net/core/dev_ioctl.c:487 sock_do_ioctl+0x1d9/0x400 net/socket.c:973 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f4edb2fec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000020000040 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 000000000073c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4edb2ff6d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff INFO: task syz-executor3:26958 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D26040 26958 8004 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline] _synchronize_rcu_expedited.constprop.0+0x7fa/0x8d0 kernel/rcu/tree_exp.h:622 synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:762 synchronize_net+0x3b/0x60 net/core/dev.c:9162 dev_deactivate_many+0x536/0xdc0 net/sched/sch_generic.c:1222 __dev_close_many+0x198/0x380 net/core/dev.c:1466 __dev_close net/core/dev.c:1491 [inline] __dev_change_flags+0x36f/0x970 net/core/dev.c:7565 dev_change_flags+0x92/0x170 net/core/dev.c:7638 devinet_ioctl+0x1489/0x1d50 net/ipv4/devinet.c:1104 inet_ioctl+0x1fc/0x370 net/ipv4/af_inet.c:954 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f9cb9738c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000020001980 RSI: 0000000000008914 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cb97396d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff INFO: task syz-executor3:26966 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D27048 26966 8004 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 devinet_ioctl+0x26f/0x1d50 net/ipv4/devinet.c:1031 inet_ioctl+0x1fc/0x370 net/ipv4/af_inet.c:954 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f9cb9717c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 00000000200000c0 RSI: 0000000000008914 RDI: 0000000000000003 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cb97186d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff INFO: task syz-executor3:26969 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D26968 26969 8004 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 devinet_ioctl+0x26f/0x1d50 net/ipv4/devinet.c:1031 inet_ioctl+0x1fc/0x370 net/ipv4/af_inet.c:954 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f9cb96f6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000020001980 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cb96f76d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff INFO: task syz-executor3:26982 blocked for more than 140 seconds. Not tainted 4.20.0+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D27048 26982 8004 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 devinet_ioctl+0x26f/0x1d50 net/ipv4/devinet.c:1031 inet_ioctl+0x1fc/0x370 net/ipv4/af_inet.c:954 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f9cb96b4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 00000000200000c0 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 000000000073c180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cb96b56d4 R13: 00000000004c351f R14: 00000000004d5f68 R15: 00000000ffffffff Showing all locks held in the system: 3 locks held by kworker/u4:3/92: 1 lock held by khungtaskd/1039: #0: 000000005132332b (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4389 2 locks held by rs:main Q:Reg/7869: #0: 000000002d011812 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1149 [inline] #0: 000000002d011812 (&rq->lock){-.-.}, at: __schedule+0x21e/0x1e90 kernel/sched/core.c:3410 #1: 000000005132332b (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 000000005132332b (rcu_read_lock){....}, at: update_curr+0x362/0xbc0 kernel/sched/fair.c:829 1 lock held by rsyslogd/7871: 2 locks held by getty/7961: #0: 000000003eeb796a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005c0f95c7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7962: #0: 000000002362b5ae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b3c5ceef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7963: #0: 00000000af48c0c7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007b0940e6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7964: #0: 00000000ec280dbb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000bf1ba661 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7965: #0: 0000000047bc5397 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006c86ffe0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7966: #0: 000000004dd0bcc3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000080b57fc2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7967: #0: 00000000520ccb20 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004df191ef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 3 locks held by kworker/0:4/8007: #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:218 [inline] #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000ac4b5405 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124 #1: 00000000a0eea4f2 ((addr_chk_work).work){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128 #2: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 3 locks held by kworker/u4:6/8204: #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:218 [inline] #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000be4da886 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124 #1: 0000000021828390 (net_cleanup_work){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128 #2: 0000000013c2e1ce (pernet_ops_rwsem){++++}, at: cleanup_net+0x126/0xb10 net/core/net_namespace.c:518 2 locks held by syz-executor0/26924: #0: 0000000013c2e1ce (pernet_ops_rwsem){++++}, at: copy_net_ns+0x289/0x4b0 net/core/net_namespace.c:433 #1: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor0/26938: #0: 0000000013c2e1ce (pernet_ops_rwsem){++++}, at: copy_net_ns+0x289/0x4b0 net/core/net_namespace.c:433 #1: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor2/26949: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor2/26954: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor2/26978: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor3/26958: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor3/26966: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor3/26969: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor3/26982: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor5/26963: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor5/26968: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor4/26973: #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 0000000068254e2d (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x425/0xc30 net/core/rtnetlink.c:5127 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1039 Comm: khungtaskd Not tainted 4.20.0+ #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbd2/0x10b0 kernel/hung_task.c:289 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 31155 Comm: kworker/1:1 Not tainted 4.20.0+ #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient gc_worker RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:766 [inline] RIP: 0010:lock_release+0x546/0xc40 kernel/locking/lockdep.c:3863 Code: 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 0b 04 00 00 48 83 3d c9 3c 2e 08 00 0f 84 4d 02 00 00 48 8b bd 28 ff ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 RSP: 0018:ffff8880a05ff780 EFLAGS: 00000286 RAX: 1ffffffff1324ffe RBX: 1ffff110140bfef7 RCX: 1ffff110140bfefd RDX: dffffc0000000000 RSI: 1ffff11013d37d7e RDI: 0000000000000286 RBP: ffff8880a05ff880 R08: ffff88809e9be380 R09: 0000000000000003 R10: 0000000000000000 R11: ffff8880ae72dc7b R12: ffff88809e9be380 R13: ffffffff8656b9d5 R14: ffffffff8b5689e0 R15: ffff8880a05ff858 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c426eceea0 CR3: 000000009eae9000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:228 [inline] rcu_read_unlock include/linux/rcupdate.h:661 [inline] gc_worker+0xa0c/0x1100 net/netfilter/nf_conntrack_core.c:1207 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352