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 kworker/1:1:24 blocked for more than 140 seconds.
      Not tainted 4.9.118-g856452b #21
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:1     D27176    24      2 0x00000000
Workqueue: ipv6_addrconf addrconf_verify_work
 ffff8801d9aee000 0000000000000000 ffff8801d4a58a80 ffff8801d9aa3000
 ffff8801db321c18 ffff8801d9bffae8 ffffffff839ebbad ffff8801d9aee8c8
 ffff8801d9aa4800 ffff8801db321c00 00fffc0000000000 ffff8801db3224e8
Call Trace:
 [<ffffffff839ed1af>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff839edb33>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff839f1fb6>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff839f1fb6>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
 [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
device loop0 blocksize: 4096
 [<ffffffff8358527e>] addrconf_verify_work+0xe/0x20 net/ipv6/addrconf.c:4366
__find_get_block_slow() failed. block=1, b_blocknr=8
 [<ffffffff8118d181>] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 [<ffffffff8118df76>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
b_state=0x00000029, b_size=512
 [<ffffffff8119d0ed>] kthread+0x26d/0x300 kernel/kthread.c:211
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 [<ffffffff839fcc5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
b_state=0x00000029, b_size=512

Showing all locks held in the system:
device loop0 blocksize: 4096
3 locks held by kworker/1:1/24:
__find_get_block_slow() failed. block=1, b_blocknr=8
 #0: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
"%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d08e>] work_static include/linux/workqueue.h:186 [inline]
"%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d08e>] set_work_data kernel/workqueue.c:617 [inline]
"%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d08e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
"%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d08e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
(addr_chk_work).work){+.+...}, at: [<ffffffff8118d0c8>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
 #2: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/519:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rcu_read_lock){......}__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8136679c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
, at: [<ffffffff8136679c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1: 
device loop0 blocksize: 4096
 (tasklist_lock){.+.+..}__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff81425fb7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
1 lock held by rsyslogd/3680:
 #0: 
__find_get_block_slow() failed. block=1, b_blocknr=8
 (b_state=0x00000029, b_size=512
&f->f_pos_lockdevice loop0 blocksize: 4096
){+.+.+.}, at: [<ffffffff815d853c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3776:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (&tty->ldisc_sem){++++++}__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff839fac52>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1: 
device loop0 blocksize: 4096
 (&ldata->atomic_read_lock){+.+...}__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff821207a2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
device loop0 blocksize: 4096
4 locks held by kworker/u4:10/28154:
__find_get_block_slow() failed. block=1, b_blocknr=8
 #0: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
"%s""netns"){.+.+.+}, at: [<ffffffff8118d08e>] work_static include/linux/workqueue.h:186 [inline]
"%s""netns"){.+.+.+}, at: [<ffffffff8118d08e>] set_work_data kernel/workqueue.c:617 [inline]
"%s""netns"){.+.+.+}, at: [<ffffffff8118d08e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
"%s""netns"){.+.+.+}, at: [<ffffffff8118d08e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
net_cleanup_work){+.+.+.}, at: [<ffffffff8118d0c8>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
 #2: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
net_mutex){+.+.+.}, at: [<ffffffff8305eb0f>] cleanup_net+0x13f/0x630 net/core/net_namespace.c:439
 #3: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by syz-executor0/30121:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (sb_writers#14__find_get_block_slow() failed. block=1, b_blocknr=8
){.+.+.+}b_state=0x00000029, b_size=512
, at: [<ffffffff815e0ddf>] sb_start_write include/linux/fs.h:1573 [inline]
, at: [<ffffffff815e0ddf>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
__find_get_block_slow() failed. block=1, b_blocknr=8
 #1: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 4096
&sb->s_type->i_mutex_key#18){++++++}__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8156ab88>] inode_lock include/linux/fs.h:766 [inline]
, at: [<ffffffff8156ab88>] do_truncate2+0x128/0x1f0 fs/open.c:61
2 locks held by syz-executor0/30125:
device loop0 blocksize: 4096
 #0:  (sb_writers#14
__find_get_block_slow() failed. block=1, b_blocknr=8
){.+.+.+}b_state=0x00000029, b_size=512
, at: [<ffffffff81568afb>] sb_start_write include/linux/fs.h:1573 [inline]
, at: [<ffffffff81568afb>] vfs_fallocate+0x2fb/0x600 fs/open.c:328
 #1:  (&sb->s_type->i_mutex_key
__find_get_block_slow() failed. block=1, b_blocknr=8
#18b_state=0x00000029, b_size=512
){++++++}device loop0 blocksize: 4096
, at: [<ffffffff818c86ce>] inode_lock include/linux/fs.h:766 [inline]
, at: [<ffffffff818c86ce>] fat_fallocate+0x10e/0x2d0 fs/fat/file.c:249
1 lock held by syz-executor4/30266:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/30267:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830bc4bb>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830bc4bb>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4067
1 lock held by syz-executor5/30183:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/30268:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor2/30207:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor3/30246:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor3/30273:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (rtnl_mutex){+.+.+.}, at: [<ffffffff830b7967>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by init/30276:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 4096
 (tty_mutex){+.+.+.}__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8211abac>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abac>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/30277:
device loop0 blocksize: 4096
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8211abac>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abac>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/30278:
device loop0 blocksize: 4096
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8211abac>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abac>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/30279:
device loop0 blocksize: 4096
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8211abac>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abac>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/30280:
device loop0 blocksize: 4096
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8211abac>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abac>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/30281:
device loop0 blocksize: 4096
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=1, b_blocknr=8
, at: [<ffffffff8211abac>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abac>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125

device loop0 blocksize: 4096
=============================================

NMI backtrace for cpu 1
__find_get_block_slow() failed. block=1, b_blocknr=8
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.118-g856452b #21
b_state=0x00000029, b_size=512
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
device loop0 blocksize: 4096
 ffff8801d8697d08 ffffffff81eb4b89
__find_get_block_slow() failed. block=1, b_blocknr=8
 0000000000000000b_state=0x00000029, b_size=512
 0000000000000001device loop0 blocksize: 4096
 0000000000000001 0000000000000001
__find_get_block_slow() failed. block=1, b_blocknr=8
 ffffffff810b9bd0b_state=0x00000029, b_size=512
 ffff8801d8697d40device loop0 blocksize: 4096
 ffffffff81ebfe87 0000000000000001
__find_get_block_slow() failed. block=1, b_blocknr=8
 0000000000000000b_state=0x00000029, b_size=512
 0000000000000003device loop0 blocksize: 4096
Call Trace:
 [<ffffffff81eb4b89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb4b89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
__find_get_block_slow() failed. block=1, b_blocknr=8
 [<ffffffff81ebfe87>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 [<ffffffff81ebfe1a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
__find_get_block_slow() failed. block=1, b_blocknr=8
 [<ffffffff810b9cd4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
b_state=0x00000029, b_size=512
 [<ffffffff81366d34>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366d34>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366d34>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366d34>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 [<ffffffff8119d0ed>] kthread+0x26d/0x300 kernel/kthread.c:211
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
 [<ffffffff839fcc5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
__find_get_block_slow() failed. block=1, b_blocknr=8
Sending NMI from CPU 1 to CPUs 0:
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
NMI backtrace for cpu 0
CPU: 0 PID: 30115 Comm: syz-executor0 Not tainted 4.9.118-g856452b #21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801ce06e000 task.stack: ffff88019b920000
RIP: 0010:[<ffffffff81ee8898>] 
c [<ffffffff81ee8898>] memcpy_erms+0x8/0x10 arch/x86/lib/memcpy_64.S:54
RSP: 0018:ffff88019b927690  EFLAGS: 00000046
RAX: ffffffff85aec66c RBX: 000000000000000c RCX: 0000000000000000
RDX: 000000000000000c RSI: ffffffff83cce936 RDI: ffffffff85aec678
RBP: ffff88019b9276b0 R08: fffffbfff0b5d8cf R09: fffffbfff0b5d8cd
R10: fffffbfff0b5d8ce R11: ffffffff85aec677 R12: ffffffff85aec66c
R13: ffffffff83cce92a R14: ffffffff83cce936 R15: 000000000000000c
FS:  00007f394d3a6700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc7a2fe8a30 CR3: 000000019ab14000 CR4: 00000000001606f0
DR0: 00000000200001c0 DR1: 00000000200001c0 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffffffff8153b385
c ffffffff85aec66c
c ffffffff83cce92a
c ffff88019b927768
c
 ffff88019b927790
c ffffffff81ee0188
c ffffffff85b16076
c ffff88019b9278c8
c
 000000000000000c
c 1ffff10033724ee1
c ffffed0033724f19
c 00000000000003e0
c
Call Trace:
 [<ffffffff81ee0188>] vsnprintf+0x4b8/0x1840 lib/vsprintf.c:2003
 [<ffffffff81ee153d>] vscnprintf+0x2d/0x60 lib/vsprintf.c:2144
 [<ffffffff8125f2b4>] vprintk_emit+0xf4/0x790 kernel/printk/printk.c:1847
 [<ffffffff8125f978>] vprintk+0x28/0x30 kernel/printk/printk.c:1913
 [<ffffffff8125f99d>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1914
 [<ffffffff8142cd8c>] vprintk_func kernel/printk/internal.h:36 [inline]
 [<ffffffff8142cd8c>] printk+0xaf/0xd7 kernel/printk/printk.c:1975
 [<ffffffff81cbac30>] __find_get_block_slow.cold.57+0xcd/0xf0 fs/buffer.c:244
 [<ffffffff816248de>] __find_get_block+0x23e/0x4c0 fs/buffer.c:1360
 [<ffffffff816256e9>] __getblk_slow fs/buffer.c:1101 [inline]
 [<ffffffff816256e9>] __getblk_gfp+0x189/0x710 fs/buffer.c:1386
 [<ffffffff8162908d>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818c51a0>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818c51a0>] fat_ent_bread+0x160/0x2f0 fs/fat/fatent.c:106
 [<ffffffff818c59bf>] fat_ent_read+0x44f/0xa20 fs/fat/fatent.c:367
 [<ffffffff818d701f>] fat_chain_add+0x40f/0x610 fs/fat/misc.c:125
 [<ffffffff818d419f>] fat_add_cluster+0xbf/0xe0 fs/fat/inode.c:105
 [<ffffffff818c87fc>] fat_fallocate+0x23c/0x2d0 fs/fat/file.c:262
 [<ffffffff81568b59>] vfs_fallocate+0x359/0x600 fs/open.c:329
 [<ffffffff8156ba63>] SYSC_fallocate fs/open.c:352 [inline]
 [<ffffffff8156ba63>] SyS_fallocate+0x53/0x90 fs/open.c:346
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fca93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
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