b_state=0x00000029, b_size=512
device loop3 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop3 blocksize: 4096
INFO: task syz-executor3:17738 blocked for more than 140 seconds.
      Not tainted 4.9.113-g47bbcd6 #10
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D30008 17738   3875 0x00000004
 ffff8801d8fb3000 ffff8801cfb20a80 ffff8801cfb20a80 ffff88019b666000
 ffff8801db321c18 ffff8801cc55f9a8 ffffffff839e909d ffffffff81235647
 0000000000000000 ffff8801d8fb38c0 0000000600000007 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea69f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff839f5cd8>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839f5cd8>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81ee7587>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff8122c270>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff8122c270>] down_write_nested+0x60/0xa0 kernel/locking/rwsem.c:174
 [<ffffffff815940f6>] inode_lock_nested include/linux/fs.h:801 [inline]
 [<ffffffff815940f6>] lock_rename+0x236/0x290 fs/namei.c:2857
 [<ffffffff815adeaa>] SYSC_renameat2 fs/namei.c:4607 [inline]
 [<ffffffff815adeaa>] SyS_renameat2+0x50a/0xae0 fs/namei.c:4546
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9f93>] 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: [<ffffffff8136675c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136675c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425de7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3679:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d81ec>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3775:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f8142>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211ee22>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by syz-executor3/17738:
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff815e0a8f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff815e0a8f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [<ffffffff815940f6>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [<ffffffff815940f6>] lock_rename+0x236/0x290 fs/namei.c:2857
1 lock held by syz-executor3/17753:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825ca2dc>] lo_ioctl+0x8c/0x1690 drivers/block/loop.c:1353
2 locks held by syz-executor3/17756:
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff815e0a8f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff815e0a8f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [<ffffffff815aa01a>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [<ffffffff815aa01a>] filename_create+0x17a/0x490 fs/namei.c:3639
2 locks held by syz-executor3/17763:
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff815e0a8f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff815e0a8f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [<ffffffff815aa01a>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [<ffffffff815aa01a>] filename_create+0x17a/0x490 fs/namei.c:3639
1 lock held by blkid/17687:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825ca2dc>] lo_ioctl+0x8c/0x1690 drivers/block/loop.c:1353
1 lock held by init/17811:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/17812:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/17813:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/17814:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/17815:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/17816:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211922c>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.113-g47bbcd6 #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d86b7d08 ffffffff81eb32a9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b9bd0 ffff8801d86b7d40
 ffffffff81ebe5a7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb32a9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb32a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebe5a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebe53a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9cd4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366cf4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366cf4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366cf4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366cf4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d0ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839fa15c>] 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
CPU: 1 PID: 17690 Comm: syz-executor2 Not tainted 4.9.113-g47bbcd6 #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801ce38b000 task.stack: ffff8801b3810000
RIP: 0010:[<ffffffff8214fb5b>] 
c [<ffffffff8214fb5b>] inb arch/x86/include/asm/io.h:316 [inline]
RIP: 0010:[<ffffffff8214fb5b>] 
c [<ffffffff8214fb5b>] io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:414
RSP: 0018:ffff8801b3817488  EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff8214fb01 RDI: ffffffff864aae78
RBP: ffff8801b3817498 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff864aae40
R13: 0000000000000020 R14: fffffbfff0c9560f R15: fffffbfff0c955d1
FS:  00007f0e76c83700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000d8bb10 CR3: 00000001c9e44000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff864aae40
c 0000000000002708
c ffff8801b38174e8
c ffffffff82151724
c
 ffffffff81ede598
c ffffffff864aae88
c ffffffff864ab07a
c ffffffff864aae40
c
 0000000000000038
c ffffffff82151870
c dffffc0000000000
c 0000000000000038
c
Call Trace:
 [<ffffffff82151724>] serial_in drivers/tty/serial/8250/8250.h:111 [inline]
 [<ffffffff82151724>] wait_for_xmitr+0x94/0x1e0 drivers/tty/serial/8250/8250_port.c:1998
 [<ffffffff8215188f>] serial8250_console_putchar+0x1f/0x60 drivers/tty/serial/8250/8250_port.c:3104
 [<ffffffff8213a0b9>] uart_console_write+0x59/0xf0 drivers/tty/serial/serial_core.c:1859
 [<ffffffff8215daa8>] serial8250_console_write+0x528/0x820 drivers/tty/serial/8250/8250_port.c:3170
 [<ffffffff8214a60f>] univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:594
 [<ffffffff8125bccd>] call_console_drivers.isra.18.constprop.28+0x1ad/0x360 kernel/printk/printk.c:1589
 [<ffffffff8125eacf>] console_unlock+0x42f/0xb40 kernel/printk/printk.c:2449
 [<ffffffff8125f628>] vprintk_emit+0x448/0x790 kernel/printk/printk.c:1903
 [<ffffffff8125f998>] vprintk+0x28/0x30 kernel/printk/printk.c:1913
 [<ffffffff8125f9bd>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1914
 [<ffffffff8142cbbc>] vprintk_func kernel/printk/internal.h:36 [inline]
 [<ffffffff8142cbbc>] printk+0xaf/0xd7 kernel/printk/printk.c:1975
 [<ffffffff82e890b2>] loop_reread_partitions.cold.35+0x40/0x4f drivers/block/loop.c:639
 [<ffffffff825c739e>] loop_set_status+0xa7e/0xfe0 drivers/block/loop.c:1180
 [<ffffffff825c7d9f>] loop_set_status64+0xbf/0x110 drivers/block/loop.c:1289
 [<ffffffff825ca595>] lo_ioctl+0x345/0x1690 drivers/block/loop.c:1379
 [<ffffffff81e56ea6>] __blkdev_driver_ioctl block/ioctl.c:294 [inline]
 [<ffffffff81e56ea6>] blkdev_ioctl+0x7b6/0x1a70 block/ioctl.c:590
 [<ffffffff81632d3e>] block_ioctl+0xde/0x120 fs/block_dev.c:1688
 [<ffffffff815b2cec>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b2cec>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b2cec>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b3d6f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b3d6f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9f93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c24 
cc9 
c00 
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c00 
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c48 
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cc1 
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c80 
c3c 
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c00 
c75 
c17 
c41 
c03 
c5c 
c24 
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c89 
cda 
cec 
c<5b> 
c0f 
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c5c 
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c