binder: BINDER_SET_CONTEXT_MGR already set
binder: 11964:11969 ioctl 40046207 0 returned -16
binder: send failed reply for transaction 45 to 11964:11966
binder: undelivered TRANSACTION_COMPLETE
binder: undelivered TRANSACTION_ERROR: 29189
INFO: task syz-executor1:11922 blocked for more than 120 seconds.
      Not tainted 4.9.101-gaef17a5 #32
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D28488 11922   3742 0x00000004
 ffff8801c4ee3000 ffff8801c9c9b480 ffff8801c9c9b480 ffff8801c4c00000
 ffff8801db221b98 ffff88019b0c79f0 ffffffff839e39bd 0000000000000002
 0000000041b58ab3 ffffffff843b8b43 00ffffff8121f220 ffff8801db222468
Call Trace:
 [<ffffffff839e4fbf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff81e3e704>] blk_mq_freeze_queue_wait+0x114/0x230 block/blk-mq.c:75
 [<ffffffff81e479fd>] blk_freeze_queue block/blk-mq.c:92 [inline]
 [<ffffffff81e479fd>] blk_mq_freeze_queue+0x1d/0x20 block/blk-mq.c:101
 [<ffffffff825c7ed2>] loop_switch drivers/block/loop.c:599 [inline]
 [<ffffffff825c7ed2>] loop_change_fd drivers/block/loop.c:685 [inline]
 [<ffffffff825c7ed2>] lo_ioctl+0x722/0x1aa0 drivers/block/loop.c:1350
 [<ffffffff81e54c06>] __blkdev_driver_ioctl block/ioctl.c:294 [inline]
 [<ffffffff81e54c06>] blkdev_ioctl+0x7b6/0x1a70 block/ioctl.c:590
 [<ffffffff816302fe>] block_ioctl+0xde/0x120 fs/block_dev.c:1688
 [<ffffffff815b052c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b052c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b052c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b15af>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b15af>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f4893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136477c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136477c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423c90>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3641:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f2a62>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211cd32>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/3739:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c783b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor1/11922:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c783b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.101-gaef17a5 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8b8fd08 ffffffff81eb1009 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b7da0 ffff8801d8b8fd40
 ffffffff81ebc307 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb1009>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb1009>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebc307>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebc29a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7ea4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364d14>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364d14>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364d14>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364d14>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad9d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f4a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 4.9.101-gaef17a5 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient gc_worker
c
task: ffff8801d99b4800 task.stack: ffff8801d99f8000
RIP: 0010:[<ffffffff812391bd>] 
c [<ffffffff812391bd>] arch_local_save_flags arch/x86/include/asm/paravirt.h:763 [inline]
RIP: 0010:[<ffffffff812391bd>] 
c [<ffffffff812391bd>] arch_local_irq_save arch/x86/include/asm/paravirt.h:785 [inline]
RIP: 0010:[<ffffffff812391bd>] 
c [<ffffffff812391bd>] lock_release+0x6d/0xb80 kernel/locking/lockdep.c:3771
RSP: 0018:ffff8801d99ffb18  EFLAGS: 00000046
RAX: 0000000000000046 RBX: ffffffff84c64fa8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801d99b50c4
RBP: ffff8801d99ffbc0 R08: ffff8801d99b5160 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff1003b336a27 R12: dffffc0000000000
R13: ffff8801d99b4800 R14: ffffffff84c64fa8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb9e6df3c0 CR3: 00000001c8af5000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 bce8459cc4093bd5
c 0000000000000046
c ffff8801d99b4800
c 0000000000000000
c
 0000000000000000
c 0000000000000002
c ffff8801d99ffbc0
c 0000000000000046
c
 0000000000000000
c ffffffff8118ae71
c 0000000000000000
c 0000000000000046
c
Call Trace:
 [<ffffffff831eef20>] seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline]
 [<ffffffff831eef20>] read_seqcount_begin include/linux/seqlock.h:163 [inline]
 [<ffffffff831eef20>] nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:325 [inline]
 [<ffffffff831eef20>] gc_worker+0x180/0x620 net/netfilter/nf_conntrack_core.c:968
 [<ffffffff8118ae71>] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092
 [<ffffffff8118bc66>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
 [<ffffffff8119ad9d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f4a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Code: 
c07 
c83 
cc0 
c03 
c38 
cd0 
c7c 
c08 
c84 
cd2 
c0f 
c85 
cd0 
c08 
c00 
c00 
c45 
c8b 
c95 
cc4 
c08 
c00 
c00 
c45 
c85 
cd2 
c0f 
c85 
c48 
c06 
c00 
c00 
c9c 
c58 
c0f 
c1f 
c44 
c00 
c00 
c48 
c89 
c45 
cb0 
c<fa> 
c66 
c0f 
c1f 
c44 
c00 
c00 
c65 
c4c 
c8b 
c2c 
c25 
c40 
c7d 
c01 
c00 
c49 
c8d 
cbd 
cc4 
c08 
c