IPVS: stopping master sync thread 9212 ...
INFO: task syz-executor0:21579 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-executor0   D29368 21579  12323 0x00000004
 ffff8801cda19800 ffff88019d4c0540 ffff880197b58000 ffff8801c4e53000
 ffff8801db321c18 ffff8801a614f7f8 ffffffff839ebdcd ffffffff81235627
 0000000000000000 ffff8801cda1a0c0 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
 [<ffffffff8156e620>] SYSC_openat fs/open.c:1099 [inline]
 [<ffffffff8156e620>] SyS_openat+0x30/0x40 fs/open.c:1093
 [<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/519:
 #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
2 locks held by rs:main Q:Reg/3683:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d859c>] __fdget_pos+0xac/0xd0 fs/file.c:781
 #1:  (sb_writers#3){.+.+.+}, at: [<ffffffff8157307e>] file_start_write include/linux/fs.h:2640 [inline]
 #1:  (sb_writers#3){.+.+.+}, at: [<ffffffff8157307e>] vfs_write+0x3ae/0x530 fs/read_write.c:556
2 locks held by getty/3781:
 #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
1 lock held by syz-executor0/12323:
 #0:  (&sb->s_type->i_mutex_key#24){++++++}, at: [<ffffffff81595061>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&sb->s_type->i_mutex_key#24){++++++}, at: [<ffffffff81595061>] lookup_slow+0x141/0x470 fs/namei.c:1645
2 locks held by syz-executor0/21579:
 #0:  (sb_writers#15){.+.+.+}, at: [<ffffffff815e0e3f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#15){.+.+.+}, at: [<ffffffff815e0e3f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#24){++++++}, at: [<ffffffff815a51a5>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#24){++++++}, at: [<ffffffff815a51a5>] do_last fs/namei.c:3312 [inline]
 #1:  (&sb->s_type->i_mutex_key#24){++++++}, at: [<ffffffff815a51a5>] path_openat+0xed5/0x3590 fs/namei.c:3534

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.119-g9dc978d #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d85a7d08 ffffffff81eb4be9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9bd0 ffff8801d85a7d40
 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: 21565 Comm: syz-executor0 Not tainted 4.9.119-g9dc978d #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cb1db000 task.stack: ffff880182c80000
RIP: 0010:[<ffffffff8135eadd>] 
c [<ffffffff8135eadd>] get_current arch/x86/include/asm/current.h:14 [inline]
RIP: 0010:[<ffffffff8135eadd>] 
c [<ffffffff8135eadd>] __sanitizer_cov_trace_pc+0xd/0x50 kernel/kcov.c:99
RSP: 0000:ffff880182c87200  EFLAGS: 00000046
RAX: ffff8801cb1db000 RBX: 0000000000000000 RCX: ffffc90000120000
RDX: 0000000000040000 RSI: ffffffff81f1c641 RDI: ffffffff83e2e420
RBP: ffff880182c87200 R08: ffff8801cb1db960 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff1003963b727 R12: ffffffff83e2e420
R13: ffffffff83cce7a0 R14: ffff8801b63df1f8 R15: 0000000000000006
FS:  00007f8535333700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa0ba3fd140 CR3: 00000001d8966000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff880182c87240
c ffffffff81f1c62b
c ffffffff843bdef0
c ffffffff83cce7a0
c
 ffff8801b63df1f8
c dffffc0000000000
c ffff8801b63df1f8
c 0000000000000006
c
 ffff880182c87258
c ffffffff81f1c79c
c 0000000000000006
c ffff880182c872a8
c
Call Trace:
 [<ffffffff81f1c62b>] check_preemption_disabled+0x3b/0x170 lib/smp_processor_id.c:51
 [<ffffffff81f1c79c>] __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
 [<ffffffff81624775>] lookup_bh_lru fs/buffer.c:1327 [inline]
 [<ffffffff81624775>] __find_get_block+0x75/0x4c0 fs/buffer.c:1356
 [<ffffffff81625749>] __getblk_slow fs/buffer.c:1101 [inline]
 [<ffffffff81625749>] __getblk_gfp+0x189/0x710 fs/buffer.c:1386
 [<ffffffff816290ed>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818b78e8>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818b78e8>] fat__get_entry+0x4c8/0x8f0 fs/fat/dir.c:100
 [<ffffffff818bf6e7>] fat_get_entry fs/fat/dir.c:128 [inline]
 [<ffffffff818bf6e7>] fat_search_long+0x277/0x1180 fs/fat/dir.c:477
 [<ffffffff818d9c54>] vfat_find+0x134/0x180 fs/fat/namei_vfat.c:708
 [<ffffffff818da431>] vfat_lookup+0xe1/0x530 fs/fat/namei_vfat.c:731
 [<ffffffff8159b55d>] lookup_open+0x63d/0x1930 fs/namei.c:3203
 [<ffffffff815a51c8>] do_last fs/namei.c:3315 [inline]
 [<ffffffff815a51c8>] path_openat+0xef8/0x3590 fs/namei.c:3534
 [<ffffffff815abb27>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8156e2fd>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8156e620>] SYSC_openat fs/open.c:1099 [inline]
 [<ffffffff8156e620>] SyS_openat+0x30/0x40 fs/open.c:1093
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c5f 
cff 
cff 
cff 
c48 
c89 
cdf 
ce8 
c42 
cd4 
c1d 
c00 
ce9 
cf9 
cfe 
cff 
cff 
c66 
c2e 
c0f 
c1f 
c84 
c00 
c00 
c00 
c00 
c00 
c0f 
c1f 
c00 
c55 
c48 
c89 
ce5 
c65 
c48 
c8b 
c04 
c25 
cc0 
c7d 
c01 
c00 
c<65> 
c8b 
c15 
c6c 
c92 
ccb 
c7e 
c81 
ce2 
c00 
c01 
c1f 
c00 
c48 
c8b 
c75 
c08 
c75 
c2b 
c8b 
c90 
c