INFO: rcu_sched self-detected stall on CPU 0-....: (124999 ticks this GP) idle=30e/1/4611686018427387906 softirq=287964/287964 fqs=31234 (t=125000 jiffies g=156333 c=156332 q=555) NMI backtrace for cpu 0 CPU: 0 PID: 15506 Comm: kworker/u4:3 Not tainted 4.18.0-rc1+ #109 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound flush_to_ldisc Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1336 print_cpu_stall kernel/rcu/tree.c:1485 [inline] check_cpu_stall.isra.60.cold.78+0x36c/0x5a6 kernel/rcu/tree.c:1553 __rcu_pending kernel/rcu/tree.c:3244 [inline] rcu_pending kernel/rcu/tree.c:3291 [inline] rcu_check_callbacks+0x23f/0xcd0 kernel/rcu/tree.c:2646 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 RIP: 0010:__sanitizer_cov_trace_pc+0x14/0x50 kernel/kcov.c:94 Code: 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 1f 43 86 7e 48 89 e5 <81> e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 90 12 00 00 83 fa 02 75 RSP: 0018:ffff88017f887238 EFLAGS: 00000296 ORIG_RAX: ffffffffffffff13 RAX: ffff8801d4926100 RBX: 000000023881cd9d RCX: ffffffff83a40d07 RDX: 0000000000000000 RSI: 0000000000000edf RDI: 0000000000000007 RBP: ffff88017f887238 R08: ffff8801d4926100 R09: 0000000000000006 R10: ffff8801d4926100 R11: 0000000000000000 R12: ffffc9000d1ec000 R13: 0000000000000600 R14: fffffffdc77e3863 R15: 0000000000000000 echo_buf drivers/tty/n_tty.c:144 [inline] __process_echoes+0x289/0x8d0 drivers/tty/n_tty.c:732 commit_echoes+0x163/0x1d0 drivers/tty/n_tty.c:764 n_tty_receive_char_fast drivers/tty/n_tty.c:1416 [inline] n_tty_receive_buf_fast drivers/tty/n_tty.c:1576 [inline] __receive_buf drivers/tty/n_tty.c:1611 [inline] n_tty_receive_buf_common+0x205b/0x2c60 drivers/tty/n_tty.c:1709 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1744 tty_ldisc_receive_buf+0xb0/0x190 drivers/tty/tty_buffer.c:456 tty_port_default_receive_buf+0x115/0x180 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:475 [inline] flush_to_ldisc+0x3fd/0x570 drivers/tty/tty_buffer.c:524 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 INFO: task kworker/u4:2:59 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D14232 59 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 _synchronize_rcu_expedited.constprop.71+0x730/0xa40 kernel/rcu/tree_exp.h:678 synchronize_sched_expedited+0x76/0xf0 kernel/rcu/tree_exp.h:715 synchronize_rcu_expedited+0x9/0x10 kernel/rcu/tree_exp.h:799 synchronize_net+0x40/0x60 net/core/dev.c:8532 rollback_registered_many+0xa89/0xef0 net/core/dev.c:7503 unregister_netdevice_many+0xfb/0x4d0 net/core/dev.c:8577 ip_tunnel_delete_nets+0x4cb/0x6c0 net/ipv4/ip_tunnel.c:1073 ipgre_tap_exit_batch_net+0x22/0x30 net/ipv4/ip_gre.c:1642 ops_exit_list.isra.7+0x105/0x160 net/core/net_namespace.c:155 cleanup_net+0x537/0xb50 net/core/net_namespace.c:523 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 INFO: task syz-fuzzer:9720 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D20696 9720 4580 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 jbd2_log_wait_commit+0x329/0x4b0 fs/jbd2/journal.c:726 jbd2_journal_stop+0xb54/0x15c0 fs/jbd2/transaction.c:1770 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:103 ext4_rmdir+0xa81/0xd40 fs/ext4/namei.c:2977 vfs_rmdir+0x19c/0x470 fs/namei.c:3890 do_rmdir+0x537/0x630 fs/namei.c:3951 __do_sys_unlinkat fs/namei.c:4113 [inline] __se_sys_unlinkat fs/namei.c:4107 [inline] __x64_sys_unlinkat+0xea/0x120 fs/namei.c:4107 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x47fc44 Code: Bad RIP value. RSP: 002b:000000c42afdd0b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047fc44 RDX: 0000000000000200 RSI: 000000c445821c20 RDI: ffffffffffffff9c RBP: 000000c42afdd110 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0055555555555555 R13: 00000000000000f5 R14: 0000000000000075 R15: 0000000000000018 INFO: task kworker/1:3:4996 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:3 D19544 4996 2 0x80000000 Workqueue: rcu_gp wait_rcu_exp_gp Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 schedule_timeout+0x1cc/0x260 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x430/0x8d0 kernel/sched/completion.c:136 flush_work+0x531/0x900 kernel/workqueue.c:2918 sync_rcu_exp_select_cpus+0x5ee/0xad0 kernel/rcu/tree_exp.h:502 rcu_exp_sel_wait_wake kernel/rcu/tree_exp.h:622 [inline] wait_rcu_exp_gp+0x78/0xc0 kernel/rcu/tree_exp.h:636 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 INFO: task syz-executor0:19318 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D18248 19318 19285 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 jbd2_log_wait_commit+0x329/0x4b0 fs/jbd2/journal.c:726 jbd2_journal_stop+0xb54/0x15c0 fs/jbd2/transaction.c:1770 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:103 ext4_unlink+0x84a/0x11f0 fs/ext4/namei.c:3046 vfs_unlink+0x2db/0x510 fs/namei.c:4010 do_unlinkat+0x6cc/0xa30 fs/namei.c:4073 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455877 Code: Bad RIP value. RSP: 002b:00007ffefc0bd4e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455877 RDX: 000000000176099b RSI: 00007ffefc0bd580 RDI: 00007ffefc0bd580 RBP: 00007ffefc0bf290 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000206 R12: 0000000001760940 R13: 0000000000000000 R14: 0000000000000bb0 R15: 00000000000b356b INFO: task syz-executor4:3070 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D18104 3070 3067 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 jbd2_log_wait_commit+0x329/0x4b0 fs/jbd2/journal.c:726 jbd2_journal_stop+0xb54/0x15c0 fs/jbd2/transaction.c:1770 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:103 ext4_evict_inode+0xc54/0x1ac0 fs/ext4/inode.c:334 evict+0x4ae/0x990 fs/inode.c:558 iput_final fs/inode.c:1506 [inline] iput+0x635/0xaa0 fs/inode.c:1532 do_unlinkat+0x733/0xa30 fs/namei.c:4079 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455877 Code: Bad RIP value. RSP: 002b:00007ffdfd2f6178 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455877 RDX: 0000000002a279f3 RSI: 00007ffdfd2f6210 RDI: 00007ffdfd2f6210 RBP: 00007ffdfd2f7f20 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000206 R12: 0000000002a27940 R13: 0000000000000000 R14: 0000000000000546 R15: 00000000000b349a INFO: task syz-executor7:18033 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D18248 18033 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 jbd2_log_wait_commit+0x329/0x4b0 fs/jbd2/journal.c:726 jbd2_journal_stop+0xb54/0x15c0 fs/jbd2/transaction.c:1770 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:103 ext4_mkdir+0xa2c/0xe60 fs/ext4/namei.c:2659 vfs_mkdir+0x42e/0x6b0 fs/namei.c:3827 do_mkdirat+0x27b/0x310 fs/namei.c:3850 __do_sys_mkdir fs/namei.c:3866 [inline] __se_sys_mkdir fs/namei.c:3864 [inline] __x64_sys_mkdir+0x5c/0x80 fs/namei.c:3864 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x454f67 Code: Bad RIP value. RSP: 002b:00007fffe90d3338 EFLAGS: 00000202 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 0000000000000028 RCX: 0000000000454f67 RDX: 00007fffe90d4014 RSI: 00000000000001ff RDI: 00007fffe90d4010 RBP: 00007fffe90d3360 R08: 0000000000000002 R09: 0000000000000004 R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000013 R13: 0000000000000000 R14: 00000000007024c0 R15: 0000000000001380 INFO: task syz-executor5:19837 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D17912 19837 31870 0x80000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 jbd2_log_wait_commit+0x329/0x4b0 fs/jbd2/journal.c:726 jbd2_complete_transaction+0x188/0x1f0 fs/jbd2/journal.c:781 ext4_sync_file+0x11f6/0x1490 fs/ext4/fsync.c:154 vfs_fsync_range+0x140/0x220 fs/sync.c:197 generic_write_sync include/linux/fs.h:2710 [inline] ext4_file_write_iter+0x6a3/0x1430 fs/ext4/file.c:270 call_write_iter include/linux/fs.h:1795 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6c6/0x9f0 fs/read_write.c:487 __kernel_write+0x10c/0x380 fs/read_write.c:506 do_acct_process+0x1148/0x1660 kernel/acct.c:520 slow_acct_process kernel/acct.c:579 [inline] acct_process+0x5f7/0x770 kernel/acct.c:605 do_exit+0x1ae0/0x2750 kernel/exit.c:855 do_group_exit+0x177/0x440 kernel/exit.c:968 get_signal+0x88e/0x1970 kernel/signal.c:2468 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2de/0x370 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b29 Code: Bad RIP value. RSP: 002b:00007fa8ab7afce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072c028 RCX: 0000000000455b29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072c028 RBP: 000000000072c028 R08: 0000000000000000 R09: 000000000072c000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4607205f R14: 00007fa8ab7b09c0 R15: 0000000000000002 INFO: task syz-executor2:19842 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D22200 19842 6467 0x80000002 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 schedule_timeout+0x1cc/0x260 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x430/0x8d0 kernel/sched/completion.c:136 __wait_rcu_gp+0x257/0x350 kernel/rcu/update.c:366 synchronize_sched.part.63+0x104/0x120 kernel/rcu/tree.c:3097 synchronize_sched+0x76/0xf0 kernel/rcu/tree.c:3098 tracepoint_synchronize_unregister include/linux/tracepoint.h:80 [inline] perf_trace_event_unreg.isra.3+0xc4/0x210 kernel/trace/trace_event_perf.c:162 perf_trace_destroy+0xc1/0x100 kernel/trace/trace_event_perf.c:237 tp_perf_event_destroy+0x15/0x20 kernel/events/core.c:8323 _free_event+0x407/0x1440 kernel/events/core.c:4445 put_event+0x48/0x60 kernel/events/core.c:4531 perf_event_release_kernel+0x8d1/0x1050 kernel/events/core.c:4637 perf_release+0x37/0x50 kernel/events/core.c:4647 __fput+0x35b/0x8b0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1b08/0x2750 kernel/exit.c:865 do_group_exit+0x177/0x440 kernel/exit.c:968 get_signal+0x88e/0x1970 kernel/signal.c:2468 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2de/0x370 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b29 Code: Bad RIP value. RSP: 002b:00007f9ad5e84ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072c0d8 RCX: 0000000000455b29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072c0d8 RBP: 000000000072c0d8 R08: 0000000000000000 R09: 000000000072c0b0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffbfebf60f R14: 00007f9ad5e859c0 R15: 0000000000000003 INFO: task syz-executor3:19836 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D25408 19836 4607 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3606 __mutex_lock_common kernel/locking/mutex.c:834 [inline] __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 sock_do_ioctl+0x2ba/0x3e0 net/socket.c:986 sock_ioctl+0x30d/0x680 net/socket.c:1097 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b29 Code: Bad RIP value. RSP: 002b:00007fe6223b4c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe6223b56d4 RCX: 0000000000455b29 RDX: 0000000020000080 RSI: 0000000000008912 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bc5aa R14: 00000000004ca4f8 R15: 0000000000000000 INFO: task syz-executor3:19843 blocked for more than 120 seconds. Not tainted 4.18.0-rc1+ #109 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D24608 19843 4607 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 jbd2_log_wait_commit+0x329/0x4b0 fs/jbd2/journal.c:726 jbd2_journal_stop+0xb54/0x15c0 fs/jbd2/transaction.c:1770 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:103 ext4_create+0x473/0x640 fs/ext4/namei.c:2458 lookup_open+0x13eb/0x1b40 fs/namei.c:3220 do_last fs/namei.c:3311 [inline] path_openat+0x1343/0x4e10 fs/namei.c:3540 do_filp_open+0x255/0x380 fs/namei.c:3574 do_sys_open+0x584/0x760 fs/open.c:1101 ksys_open include/linux/syscalls.h:1270 [inline] __do_sys_creat fs/open.c:1159 [inline] __se_sys_creat fs/open.c:1157 [inline] __x64_sys_creat+0x61/0x80 fs/open.c:1157 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b29 Code: Bad RIP value. RSP: 002b:00007fe622393c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fe6223946d4 RCX: 0000000000455b29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 000000000072bf50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bba24 R14: 00000000004c8908 R15: 0000000000000001 Showing all locks held in the system: 3 locks held by kworker/1:1/27: #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000c70fca7b ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 00000000daefbb1a ((addr_chk_work).work){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 #2: 000000001eb8c3df (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 5 locks held by kworker/u4:2/59: #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000de29e1f4 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 0000000076413746 (net_cleanup_work){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 #2: 0000000070fc803a (pernet_ops_rwsem){++++}, at: cleanup_net+0x12e/0xb50 net/core/net_namespace.c:490 #3: 000000001eb8c3df (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #4: 00000000e7023db8 (rcu_sched_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: 00000000e7023db8 (rcu_sched_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited.constprop.71+0x80d/0xa40 kernel/rcu/tree_exp.h:659 1 lock held by khungtaskd/899: #0: 00000000da315659 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 2 locks held by rs:main Q:Reg/4466: #0: 0000000047760ad5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000751cf969 (sb_writers#6){.+.+}, at: file_start_write include/linux/fs.h:2739 [inline] #1: 00000000751cf969 (sb_writers#6){.+.+}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4468: 2 locks held by getty/4559: #0: 00000000166bfda9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fbeceb59 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4560: #0: 00000000c3fb3e33 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000651ff8fd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4561: #0: 0000000055d148e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000078ba72 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4562: #0: 0000000026c79363 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000033d403ee (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4563: #0: 000000005f34d830 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000cda01d75 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4564: #0: 00000000a4c1264c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e26cf777 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4565: #0: 0000000027415c6a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000669ee411 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 3 locks held by syz-fuzzer/9720: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 000000005c4e2bd1 (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 000000005c4e2bd1 (&type->i_mutex_dir_key/1){+.+.}, at: do_rmdir+0x38f/0x630 fs/namei.c:3939 #2: 0000000037a8c1b0 (&type->i_mutex_dir_key){++++}, at: inode_lock include/linux/fs.h:715 [inline] #2: 0000000037a8c1b0 (&type->i_mutex_dir_key){++++}, at: vfs_rmdir+0xe0/0x470 fs/namei.c:3880 2 locks held by kworker/1:3/4996: #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000b13d968c ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 0000000025458e22 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 3 locks held by syz-executor0/19318: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000f0fa53a9 (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000f0fa53a9 (&type->i_mutex_dir_key/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 #2: 0000000086f9bbdd (&sb->s_type->i_mutex_key#12){++++}, at: inode_lock include/linux/fs.h:715 [inline] #2: 0000000086f9bbdd (&sb->s_type->i_mutex_key#12){++++}, at: vfs_unlink+0xd1/0x510 fs/namei.c:4001 1 lock held by syz-executor5/31870: #0: 000000005aaa8e26 (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline] #0: 000000005aaa8e26 (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline] #0: 000000005aaa8e26 (&acct->lock#2){+.+.}, at: acct_process+0x3c2/0x770 kernel/acct.c:605 2 locks held by syz-executor4/3070: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 000000008ab24822 (sb_internal){.+.+}, at: sb_start_intwrite include/linux/fs.h:1601 [inline] #1: 000000008ab24822 (sb_internal){.+.+}, at: ext4_evict_inode+0x73d/0x1ac0 fs/ext4/inode.c:250 6 locks held by kworker/u4:3/15506: 3 locks held by kworker/1:4/15897: #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000327f1df2 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 000000002f97469b (deferred_process_work){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 #2: 000000001eb8c3df (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor7/18033: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000e5908872 (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000e5908872 (&type->i_mutex_dir_key/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3645 2 locks held by syz-executor5/19837: #0: 000000005aaa8e26 (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline] #0: 000000005aaa8e26 (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline] #0: 000000005aaa8e26 (&acct->lock#2){+.+.}, at: acct_process+0x3c2/0x770 kernel/acct.c:605 #1: 00000000751cf969 (sb_writers#6){.+.+}, at: file_start_write_trylock include/linux/fs.h:2746 [inline] #1: 00000000751cf969 (sb_writers#6){.+.+}, at: do_acct_process+0x133c/0x1660 kernel/acct.c:517 1 lock held by syz-executor2/19842: #0: 00000000016b620b (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:235 1 lock held by syz-executor3/19836: #0: 000000001eb8c3df (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor3/19843: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: do_last fs/namei.c:3308 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: path_openat+0x1316/0x4e10 fs/namei.c:3540 2 locks held by syz-executor3/19844: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 2 locks held by syz-executor3/19845: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 2 locks held by syz-executor3/19846: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: do_last fs/namei.c:3308 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: path_openat+0x1316/0x4e10 fs/namei.c:3540 1 lock held by syz-executor3/19847: #0: 000000001eb8c3df (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor3/19848: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: do_last fs/namei.c:3308 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: path_openat+0x1316/0x4e10 fs/namei.c:3540 2 locks held by syz-executor3/19849: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 2 locks held by syz-executor3/19850: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000f3db727f (&sb->s_type->i_mutex_key#12){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 2 locks held by syz-executor3/19851: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: do_last fs/namei.c:3308 [inline] #1: 00000000874e3b4e (&type->i_mutex_dir_key){++++}, at: path_openat+0x1316/0x4e10 fs/namei.c:3540 2 locks held by syz-executor1/19839: #0: 00000000751cf969 (sb_writers#6){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000751cf969 (sb_writers#6){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000a163232b (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000a163232b (&type->i_mutex_dir_key/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3645 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 899 Comm: khungtaskd Not tainted 4.18.0-rc1+ #109 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15506 Comm: kworker/u4:3 Not tainted 4.18.0-rc1+ #109 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound flush_to_ldisc RIP: 0010:__write_once_size include/linux/compiler.h:215 [inline] RIP: 0010:write_comp_data+0x6c/0x70 kernel/kcov.c:144 Code: 00 00 4e 8d 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 <5d> c3 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 1f 43 86 7e 48 RSP: 0018:ffff88017f887228 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 000000024d7a3360 RCX: ffffffff83a40cd9 RDX: 0000000000000000 RSI: 0000000000000082 RDI: 0000000000000001 RBP: ffff88017f887228 R08: ffff8801d4926100 R09: 0000000000000006 R10: ffff8801d4926100 R11: 0000000000000000 R12: ffffc9000d1ec000 R13: 0000000000000600 R14: 0000000000000000 R15: 00000000000000ff FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f40a9fda000 CR3: 0000000008e6a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_const_cmp1+0x1a/0x20 kernel/kcov.c:174 __process_echoes+0x249/0x8d0 drivers/tty/n_tty.c:733 commit_echoes+0x163/0x1d0 drivers/tty/n_tty.c:764 n_tty_receive_char_fast drivers/tty/n_tty.c:1416 [inline] n_tty_receive_buf_fast drivers/tty/n_tty.c:1576 [inline] __receive_buf drivers/tty/n_tty.c:1611 [inline] n_tty_receive_buf_common+0x205b/0x2c60 drivers/tty/n_tty.c:1709 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1744 tty_ldisc_receive_buf+0xb0/0x190 drivers/tty/tty_buffer.c:456 tty_port_default_receive_buf+0x115/0x180 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:475 [inline] flush_to_ldisc+0x3fd/0x570 drivers/tty/tty_buffer.c:524 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412