binder_alloc: binder_alloc_mmap_handler: 16914 20000000-20002000 already mapped failed -16
binder: 16914:16915 transaction failed 29189/-22, size 40-8 line 3010
binder: 16914:16918 BC_INCREFS_DONE u00000000204edf8a no match
binder: undelivered TRANSACTION_ERROR: 29189
Buffer I/O error on dev loop0, logical block 0, async page read
INFO: task syz-executor1:16864 blocked for more than 120 seconds.
      Not tainted 4.9.92-g13b40d3 #12
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D26240 16864   3865 0x20020004
 ffff8801cee51800 0000000000000000 ffff8801bb762f40 ffff8801d9b41800
 ffff8801db321b98 ffff880199f7f090 ffffffff838a76cb 0000000041b58ab3
 ffffffff84193da8 00ffffff8123ac80 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a8c6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3551
 [<ffffffff838b4c2c>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a6e7e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5173
 [<ffffffff838aa0e9>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff838aa0e9>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff838a97c7>] __wait_on_bit+0x57/0x120 kernel/sched/wait.c:383
 [<ffffffff838a9b40>] out_of_line_wait_on_bit+0xf0/0x130 kernel/sched/wait.c:396
 [<ffffffff8162409b>] wait_on_bit_io include/linux/wait.h:1070 [inline]
 [<ffffffff8162409b>] __wait_on_buffer fs/buffer.c:124 [inline]
 [<ffffffff8162409b>] wait_on_buffer include/linux/buffer_head.h:347 [inline]
 [<ffffffff8162409b>] __bread_slow fs/buffer.c:1229 [inline]
 [<ffffffff8162409b>] __bread_gfp+0x1db/0x280 fs/buffer.c:1423
 [<ffffffff819f7b61>] __bread include/linux/buffer_head.h:389 [inline]
 [<ffffffff819f7b61>] btrfs_read_dev_one_super+0xb1/0x270 fs/btrfs/disk-io.c:3359
 [<ffffffff819f7d8c>] btrfs_read_dev_super+0x6c/0xd0 fs/btrfs/disk-io.c:3394
 [<ffffffff81a87b33>] btrfs_get_bdev_and_sb+0x153/0x2d0 fs/btrfs/volumes.c:304
 [<ffffffff81a87e5d>] __btrfs_open_devices+0x1ad/0xb10 fs/btrfs/volumes.c:986
 [<ffffffff81a8de91>] btrfs_open_devices+0xa1/0xb0 fs/btrfs/volumes.c:1059
 [<ffffffff81980515>] btrfs_mount+0xca5/0x2c00 fs/btrfs/super.c:1603
 [<ffffffff8157ac2f>] mount_fs+0x27f/0x350 fs/super.c:1206
 [<ffffffff815d8c90>] vfs_kern_mount.part.21+0xd0/0x3e0 fs/namespace.c:991
 [<ffffffff815d8fe0>] vfs_kern_mount+0x40/0x60 fs/namespace.c:973
 [<ffffffff8197fb5e>] mount_subvol fs/btrfs/super.c:1395 [inline]
 [<ffffffff8197fb5e>] btrfs_mount+0x2ee/0x2c00 fs/btrfs/super.c:1566
 [<ffffffff8157ac2f>] mount_fs+0x27f/0x350 fs/super.c:1206
 [<ffffffff815d8c90>] vfs_kern_mount.part.21+0xd0/0x3e0 fs/namespace.c:991
 [<ffffffff815e0401>] vfs_kern_mount fs/namespace.c:2509 [inline]
 [<ffffffff815e0401>] do_new_mount fs/namespace.c:2512 [inline]
 [<ffffffff815e0401>] do_mount+0x3e1/0x28b0 fs/namespace.c:2834
 [<ffffffff81679c90>] C_SYSC_mount fs/compat.c:810 [inline]
 [<ffffffff81679c90>] compat_SyS_mount+0xd0/0x1070 fs/compat.c:775
 [<ffffffff81006f95>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006f95>] do_fast_syscall_32+0x2f5/0x870 arch/x86/entry/common.c:387
 [<ffffffff838b9c90>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by khungtaskd/515:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813722b5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813722b5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81236de0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3752:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b67a2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff8200a8f4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor1/16864:
 #0:  (uuid_mutex){+.+.+.}, at: [<ffffffff81a8de17>] btrfs_open_devices+0x27/0xb0 fs/btrfs/volumes.c:1054

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

NMI backtrace for cpu 0
CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.92-g13b40d3 #12
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d86dfd00 ffffffff81d95109 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bb8f0 ffff8801d86dfd38
 ffffffff81da025d 0000000000000000 0000000000000000 ffff8801cee53418
Call Trace:
 [<ffffffff81d95109>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d95109>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da025d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0397>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb9e4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81372880>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81372880>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81372880>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81372880>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119c0dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b875c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff838b7216