b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
INFO: task syz-executor0:12689 blocked for more than 120 seconds.
      Not tainted 4.9.96-g71fce1e #10
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29816 12689   3873 0x00000004
 ffff8801d7908000 ffff8801bdacb480 ffff8801c02739c0 ffff8801d5368000
 ffff8801db321b98 ffff8801d49f78b0 ffffffff839e240d ffffffff81233817
 0000000000000000 ffff8801d79088c0 0000000600000007 ffff8801db322468
Call Trace:
 [<ffffffff839e3a0f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839ede34>] rwsem_down_read_failed+0x1e4/0x320 kernel/locking/rwsem-xadd.c:260
 [<ffffffff81ee4e48>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<ffffffff839ecd62>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<ffffffff839ecd62>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<ffffffff815a2f2c>] inode_lock_shared include/linux/fs.h:776 [inline]
 [<ffffffff815a2f2c>] do_last fs/namei.c:3314 [inline]
 [<ffffffff815a2f2c>] path_openat+0x17dc/0x3590 fs/namei.c:3534
 [<ffffffff815a8fa7>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8156b77d>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8156ba5d>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff8156ba5d>] SyS_open+0x2d/0x40 fs/open.c:1085
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f3313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/518:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646ec>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646ec>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423ce0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3673:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d579c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3769:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f14b2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211c792>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
2 locks held by syz-executor0/12689:
 #0:  (sb_writers#12){.+.+.+}, at: [<ffffffff815de03f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#12){.+.+.+}, at: [<ffffffff815de03f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2f2c>] inode_lock_shared include/linux/fs.h:776 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2f2c>] do_last fs/namei.c:3314 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2f2c>] path_openat+0x17dc/0x3590 fs/namei.c:3534
2 locks held by syz-executor0/12694:
 #0:  (sb_writers#12){.+.+.+}, at: [<ffffffff815de03f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#12){.+.+.+}, at: [<ffffffff815de03f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2625>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2625>] do_last fs/namei.c:3312 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2625>] path_openat+0xed5/0x3590 fs/namei.c:3534
2 locks held by syz-executor0/12701:
 #0:  (sb_writers#12){.+.+.+}, at: [<ffffffff815de03f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#12){.+.+.+}, at: [<ffffffff815de03f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2f2c>] inode_lock_shared include/linux/fs.h:776 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2f2c>] do_last fs/namei.c:3314 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){+++++.}, at: [<ffffffff815a2f2c>] path_openat+0x17dc/0x3590 fs/namei.c:3534

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

NMI backtrace for cpu 1
CPU: 1 PID: 518 Comm: khungtaskd Not tainted 4.9.96-g71fce1e #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d863fd08 ffffffff81eb0b69 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b7d60 ffff8801d863fd40
 ffffffff81ebbe97 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb0b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebbe97>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebbe2a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7e64>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364c84>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c84>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c84>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c84>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad5d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f34dc>] 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: 12687 Comm: syz-executor2 Not tainted 4.9.96-g71fce1e #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d790e000 task.stack: ffff8801ba380000
RIP: 0010:[<ffffffff8214d0fb>] 
c [<ffffffff8214d0fb>] inb arch/x86/include/asm/io.h:316 [inline]
RIP: 0010:[<ffffffff8214d0fb>] 
c [<ffffffff8214d0fb>] io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:414
RSP: 0018:ffff8801ba3874e8  EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff8214d0a1 RDI: ffffffff862aae78
RBP: ffff8801ba3874f8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff862aae40
R13: 0000000000000020 R14: fffffbfff0c5560f R15: fffffbfff0c555d1
FS:  00007f521ebd5700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c42663d000 CR3: 00000001cc40e000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffffffff862aae40
c 000000000000270a
c ffff8801ba387548
c ffffffff8214ecc4
c
 ffffffff81edbe88
c ffffffff862aae88
c ffffffff862ab07a
c ffffffff862aae40
c
 0000000000000067
c ffffffff8214ee10
c dffffc0000000000
c 0000000000000067
c
Call Trace:
 [<ffffffff8214ecc4>] serial_in drivers/tty/serial/8250/8250.h:111 [inline]
 [<ffffffff8214ecc4>] wait_for_xmitr+0x94/0x1e0 drivers/tty/serial/8250/8250_port.c:1997
 [<ffffffff8214ee2f>] serial8250_console_putchar+0x1f/0x60 drivers/tty/serial/8250/8250_port.c:3103
 [<ffffffff82137659>] uart_console_write+0x59/0xf0 drivers/tty/serial/serial_core.c:1859
 [<ffffffff8215b038>] serial8250_console_write+0x528/0x820 drivers/tty/serial/8250/8250_port.c:3169
 [<ffffffff82147baf>] univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:594
 [<ffffffff81259e7d>] call_console_drivers.isra.18.constprop.28+0x1ad/0x360 kernel/printk/printk.c:1589
 [<ffffffff8125cc7f>] console_unlock+0x42f/0xb40 kernel/printk/printk.c:2449
 [<ffffffff8125d7d8>] vprintk_emit+0x448/0x790 kernel/printk/printk.c:1903
 [<ffffffff8125db48>] vprintk+0x28/0x30 kernel/printk/printk.c:1913
 [<ffffffff8125db6d>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1914
 [<ffffffff8142aab5>] vprintk_func kernel/printk/internal.h:36 [inline]
 [<ffffffff8142aab5>] printk+0xaf/0xd7 kernel/printk/printk.c:1975
 [<ffffffff81cb9046>] __ext4_warning.cold.131+0x51/0x56 fs/ext4/super.c:664
 [<ffffffff817dfd90>] ext4_resize_begin+0x1b0/0x1e0 fs/ext4/resize.c:43
 [<ffffffff81762b76>] ext4_ioctl+0x1166/0x3620 fs/ext4/ioctl.c:713
 [<ffffffff815b051c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b051c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b051c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b159f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b159f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f3313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c24 
cc9 
c00 
c00 
c00 
c49 
c8d 
c7c 
c24 
c38 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
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c48 
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c48 
cc1 
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cd3 
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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 
c18 
cc3 
c3e 
cff 
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cc2 
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cc3 
c3e 
cff 
ceb 
c