kworker/dying (3971) used greatest stack depth: 13720 bytes left
INFO: task syz-executor3:8473 blocked for more than 120 seconds.
Not tainted 4.15.0-rc2+ #209
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3 D24320 8473 3321 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2799 [inline]
__schedule+0x8eb/0x2060 kernel/sched/core.c:3375
schedule+0xf5/0x430 kernel/sched/core.c:3434
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3492
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355
__blkdev_driver_ioctl block/ioctl.c:303 [inline]
blkdev_ioctl+0x1759/0x1e00 block/ioctl.c:601
block_ioctl+0xea/0x130 fs/block_dev.c:1860
vfs_ioctl fs/ioctl.c:46 [inline]
do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007fc963a7fc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 000000002002df18 RSI: 0000000000004c04 RDI: 0000000000000018
RBP: 000000000000039b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2728
R13: 00000000ffffffff R14: 0000000000758098 R15: 0000000000000000
Showing all locks held in the system:
2 locks held by khungtaskd/674:
#0: (rcu_read_lock){....}, at: [<000000003e010448>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<000000003e010448>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
#1: (tasklist_lock){.?.?}, at: [<0000000051c42851>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554
2 locks held by getty/3066:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3067:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3068:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3069:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3070:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3071:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
1 lock held by syz-executor3/8473:
#0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000ef507737>] lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355
1 lock held by syz-executor3/8479:
#0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000ef507737>] lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355
2 locks held by getty/8560:
#0: (&tty->ldisc_sem){++++}, at: [<0000000094f7ec2f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a9a04587>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 674 Comm: khungtaskd Not tainted 4.15.0-rc2+ #209
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+0x194/0x257 lib/dump_stack.c:53
nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x122/0x180 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_task kernel/hung_task.c:132 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
watchdog+0x90c/0xd60 kernel/hung_task.c:249
kthread+0x37a/0x440 kernel/kthread.c:238
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc2+ #209
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0x549/0x47f0 kernel/locking/lockdep.c:3450
RSP: 0018:ffff8801db407768 EFLAGS: 00000002
RAX: 000000000000000e RBX: ffffffff85e2fc08 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff85e2fc2c
RBP: ffff8801db407af0 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000000 R11: ffffffff87489d60 R12: ffffffff85e2f380
R13: 0000000000000034 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f39cc6f5140 CR3: 00000001d1392000 CR4: 00000000001406f0
Call Trace:
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline]
read_seqcount_begin include/linux/seqlock.h:164 [inline]
ktime_get+0x12f/0x3a0 kernel/time/timekeeping.c:762
tick_nohz_irq_enter kernel/time/tick-sched.c:1120 [inline]
tick_irq_enter+0x9e/0x390 kernel/time/tick-sched.c:1141
irq_enter+0xbd/0xe0 kernel/softirq.c:346
scheduler_ipi+0x246/0x830 kernel/sched/core.c:1793
smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277
reschedule_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:819
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffffffff85e07d08 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffffffff0bc0fa4 RCX: 0000000000000000
RDX: 1ffffffff0bd968c RSI: 0000000000000001 RDI: ffffffff85ecb460
RBP: ffffffff85e07d08 R08: ffffffff85be9ae0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff85e07dc0 R14: ffffffff865eaa20 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline]
default_idle+0xbf/0x460 arch/x86/kernel/process.c:348
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:339
default_idle_call+0x36/0x90 kernel/sched/idle.c:98
cpuidle_idle_call kernel/sched/idle.c:156 [inline]
do_idle+0x24a/0x3b0 kernel/sched/idle.c:246
cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:351
rest_init+0xed/0xf0 init/main.c:435
start_kernel+0x729/0x74f init/main.c:710
x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378
x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237
Code: c1 e0 02 44 88 53 21 83 e1 f8 09 d1 09 c1 42 8d 04 cd 00 00 00 00 83 e1 f7 41 89 c9 41 09 c1 44 88 4b 22 0f b7 55 20 0f b7 43 22 e2 04 83 e0 0f 09 d0 48 89 fa 66 89 43 22 48 c1 ea 03 48 b8