INFO: task syz-executor6:12950 blocked for more than 120 seconds.
Not tainted 4.15.0+ #287
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6 D25520 12950 4096 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2845 [inline]
__schedule+0x8eb/0x2060 kernel/sched/core.c:3421
schedule+0xf5/0x430 kernel/sched/core.c:3480
blk_mq_freeze_queue_wait+0x1bb/0x400 block/blk-mq.c:136
blk_freeze_queue+0x4a/0x80 block/blk-mq.c:165
blk_mq_freeze_queue+0x15/0x20 block/blk-mq.c:174
loop_change_fd drivers/block/loop.c:667 [inline]
lo_ioctl+0x10ce/0x1b70 drivers/block/loop.c:1361
__blkdev_driver_ioctl block/ioctl.c:303 [inline]
blkdev_ioctl+0x1759/0x1e00 block/ioctl.c:601
block_ioctl+0xde/0x120 fs/block_dev.c:1860
vfs_ioctl fs/ioctl.c:46 [inline]
do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x453299
RSP: 002b:00007fe30a36ac58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299
RDX: 0000000000000013 RSI: 0000000000004c06 RDI: 0000000000000013
RBP: 0000000000000414 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5280
R13: 00000000ffffffff R14: 00007fe30a36b6d4 R15: 0000000000000000
Showing all locks held in the system:
2 locks held by khungtaskd/760:
#0: (rcu_read_lock){....}, at: [<00000000ec362883>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000ec362883>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<000000003cf347e8>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
2 locks held by getty/4013:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4014:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4015:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4016:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4017:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4018:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4019:
#0: (&tty->ldisc_sem){++++}, at: [<0000000004a92532>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000092570ddb>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
1 lock held by syz-executor6/12950:
#0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000983a6ad3>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355
1 lock held by syz-executor6/12964:
#0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000983a6ad3>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355
1 lock held by blkid/12992:
#0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000983a6ad3>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 760 Comm: khungtaskd Not tainted 4.15.0+ #287
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+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:542
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+ #287
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:trace_hardirqs_off+0x0/0x10 arch/x86/include/asm/paravirt.h:772
RSP: 0018:ffff8801db407c28 EFLAGS: 00000093
RAX: ffffffff86a2c340 RBX: dffffc0000000000 RCX: ffffffff81611db2
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000082
RBP: ffff8801db407d18 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003b680f8a
R13: ffff8801db407cf0 R14: 0000000000000093 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2e56287169 CR3: 0000000006a22001 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
tick_nohz_irq_enter kernel/time/tick-sched.c:1148 [inline]
tick_irq_enter+0x9e/0x390 kernel/time/tick-sched.c:1169
irq_enter+0xb6/0xd0 kernel/softirq.c:346
scheduler_ipi+0x23d/0x820 kernel/sched/core.c:1794
smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277
reschedule_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:962
</IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffffffff86a07c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffffffff0d40f8a RCX: 0000000000000000
RDX: 1ffffffff0d59288 RSI: 0000000000000001 RDI: ffffffff86ac9440
RBP: ffffffff86a07c38 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff86a07cf0 R14: ffffffff8725c920 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline]
default_idle+0xbf/0x430 arch/x86/kernel/process.c:354
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345
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+0x104/0x120 kernel/sched/idle.c:351
rest_init+0xed/0xf0 init/main.c:436
start_kernel+0x7f1/0x819 init/main.c:716
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: 00 e9 d4 fe ff ff e8 e0 e7 51 00 eb 93 e8 79 e8 51 00 e9 05 ff ff ff e8 ef e7 51 00 e9 2b ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 48 8b 7d 08 e8 33 fd ff ff 5d c3 90 55 48 89 e5 41