sd 0:0:1:0: [sg0] tag#3240 CDB[10]: 35 8c 32 2c 9b fb 41 ae b8 92 22 39 85 a7 e6 e2
sd 0:0:1:0: [sg0] tag#3240 CDB[20]: 3c ed bd fd 26 df 66 a3 34 21 57 a9 8a 58 e1 c9
sd 0:0:1:0: [sg0] tag#3240 CDB[30]: df 3a 41 13 66 90 51 08 c7 e2 fe 57 fe bd 0e 1f
sd 0:0:1:0: [sg0] tag#3240 CDB[40]: 59 f8 56 b6 33 41 05 82 e8 61 56 ad 98 85 4d 3d
sd 0:0:1:0: [sg0] tag#3240 CDB[50]: d7 59 9c 98 43 3b 3b 1b a8 51
INFO: rcu_sched self-detected stall on CPU
	0-....: (124999 ticks this GP) idle=ac2/1/4611686018427387906 softirq=80843/80843 fqs=31217 
	 (t=125000 jiffies g=44468 c=44467 q=383)
NMI backtrace for cpu 0
CPU: 0 PID: 8736 Comm: kworker/u4:5 Not tainted 4.18.0-rc1+ #110
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
Call Trace:
 <IRQ>
 __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
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101
Code: 5d c3 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 ff de 85 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 20 48 8b 88 98 12 00 00 8b 80 94 12 00 00 48 8b 11 48 
RSP: 0018:ffff8801b1a1f238 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff880180642780 RBX: 00000002a0586f16 RCX: ffffffff83a43349
RDX: 0000000000000000 RSI: ffffffff83a43364 RDI: 0000000000000001
RBP: ffff8801b1a1f238 R08: ffff880180642780 R09: 0000000000000006
R10: ffff880180642780 R11: 0000000000000000 R12: ffffc90006fa2000
R13: 0000000000001856 R14: 00000002a0586f16 R15: 00000000000000ff
 __process_echoes+0x264/0x8d0 drivers/tty/n_tty.c:731
 commit_echoes+0x163/0x1d0 drivers/tty/n_tty.c:764
 n_tty_receive_char_inline drivers/tty/n_tty.c:1388 [inline]
 n_tty_receive_buf_standard drivers/tty/n_tty.c:1550 [inline]
 __receive_buf drivers/tty/n_tty.c:1613 [inline]
 n_tty_receive_buf_common+0x9d4/0x2c60 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