b_state=0x00000029, b_size=512
device loop6 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop6 blocksize: 2048
INFO: task syz-executor6:22043 blocked for more than 140 seconds.
      Not tainted 4.9.119-g9dc978d #23
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D29656 22043   3853 0x00000004
 ffff880198b34800 0000000000000000 ffff8801bf1bc000 ffff8801d4e2c800
 ffff8801db321c18 ffff88019c777808 ffffffff839ebdcd ffffffff81235627
 0000000000000000 ffff880198b350c0 0000000600000007 ffff8801db3224e8
Call Trace:
 [<ffffffff839ed3cf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff839f8a08>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839f8a08>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81ee8ec7>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff839f67dc>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff839f67dc>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff815a51a5>] inode_lock include/linux/fs.h:766 [inline]
 [<ffffffff815a51a5>] do_last fs/namei.c:3312 [inline]
 [<ffffffff815a51a5>] path_openat+0xed5/0x3590 fs/namei.c:3534
 [<ffffffff815abb27>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8156e2fd>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8156e5dd>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff8156e5dd>] SyS_open+0x2d/0x40 fs/open.c:1085
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/520:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813667bc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813667bc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81426027>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3656:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d859c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3752:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839fae72>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff821208d2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by syz-executor6/22043:
 #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff815e0e3f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff815e0e3f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#18){++++++}, at: [<ffffffff815a51a5>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#18){++++++}, at: [<ffffffff815a51a5>] do_last fs/namei.c:3312 [inline]
 #1:  (&sb->s_type->i_mutex_key#18){++++++}, at: [<ffffffff815a51a5>] path_openat+0xed5/0x3590 fs/namei.c:3534
1 lock held by init/22060:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/22061:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/22062:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/22063:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/22064:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/22065:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8211acdc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125

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

NMI backtrace for cpu 1
CPU: 1 PID: 520 Comm: khungtaskd Not tainted 4.9.119-g9dc978d #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d869fd08 ffffffff81eb4be9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9bd0 ffff8801d869fd40
 ffffffff81ebfee7 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebfee7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebfe7a>] 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
 [<ffffffff81366d54>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366d54>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366d54>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366d54>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d0ed>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839fce9c>] 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: 22025 Comm: syz-executor4 Not tainted 4.9.119-g9dc978d #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d7b61800 task.stack: ffff88019b918000
RIP: 0010:[<ffffffff821516ab>] 
c [<ffffffff821516ab>] inb arch/x86/include/asm/io.h:316 [inline]
RIP: 0010:[<ffffffff821516ab>] 
c [<ffffffff821516ab>] io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:414
RSP: 0018:ffff88019b91f730  EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff82151651 RDI: ffffffff864aaeb8
RBP: ffff88019b91f740 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff864aae80
R13: 0000000000000020 R14: fffffbfff0c95617 R15: fffffbfff0c955d9
FS:  00007fe37aed2700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa33ef07a30 CR3: 00000001d30c3000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 00000000200001c0 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffffffff864aae80
c 0000000000002709
c ffff88019b91f790
c ffffffff82153274
c
 ffffffff81edfed8
c ffffffff864aaec8
c ffffffff864ab0ba
c ffffffff864aae80
c
 0000000000000062
c ffffffff821533c0
c dffffc0000000000
c 0000000000000062
c
Call Trace:
 [<ffffffff82153274>] serial_in drivers/tty/serial/8250/8250.h:111 [inline]
 [<ffffffff82153274>] wait_for_xmitr+0x94/0x1e0 drivers/tty/serial/8250/8250_port.c:1998
 [<ffffffff821533df>] serial8250_console_putchar+0x1f/0x60 drivers/tty/serial/8250/8250_port.c:3104
 [<ffffffff8213bc09>] uart_console_write+0x59/0xf0 drivers/tty/serial/serial_core.c:1859
 [<ffffffff8215f5f8>] serial8250_console_write+0x528/0x820 drivers/tty/serial/8250/8250_port.c:3170
 [<ffffffff8214c15f>] univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:594
 [<ffffffff8125bcad>] call_console_drivers.isra.18.constprop.28+0x1ad/0x360 kernel/printk/printk.c:1589
 [<ffffffff8125eaaf>] console_unlock+0x42f/0xb40 kernel/printk/printk.c:2449
 [<ffffffff8125f608>] vprintk_emit+0x448/0x790 kernel/printk/printk.c:1903
 [<ffffffff8125f978>] vprintk+0x28/0x30 kernel/printk/printk.c:1913
 [<ffffffff8125f99d>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1914
 [<ffffffff8142cdfc>] vprintk_func kernel/printk/internal.h:36 [inline]
 [<ffffffff8142cdfc>] printk+0xaf/0xd7 kernel/printk/printk.c:1975
 [<ffffffff82ec3a0d>] binder_ioctl.cold.79+0x61/0x121 drivers/android/binder.c:4837
 [<ffffffff815b309c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b309c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b309c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b411f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b411f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c24 
cc9 
c00 
c00 
c00 
c49 
c8d 
c7c 
c24 
c38 
c48 
cb8 
c00 
c00 
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c00 
c00 
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c48 
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cfa 
c48 
cc1 
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c03 
cd3 
ce3 
c80 
c3c 
c02 
c00 
c75 
c17 
c41 
c03 
c5c 
c24 
c38 
c89 
cda 
cec 
c<5b> 
c0f 
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cc0 
c41 
c5c 
c5d 
cc3 
ce8 
ce8 
ca7 
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cff 
ceb 
cc2 
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c41 
ca8 
c3e 
cff 
ceb 
c