INFO: task syz-executor4:12981 blocked for more than 140 seconds.
      Not tainted 4.9.122-g54068d6 #26
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D29384 12981   3885 0x00000004
 ffff8801985a0000 ffff8801baef4fc0 ffff8801baef4fc0 ffff88019da73000
 ffff8801db321c18 ffff8801c9daf808 ffffffff839efdcd ffffffff812378c7
 0000000000000000 ffff8801985a08c0 0000000600000007 ffff8801db3224e8
Call Trace:
 [<ffffffff839f13cf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff839fca08>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839fca08>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81eecb47>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff839fa7dc>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff839fa7dc>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff815a88e5>] inode_lock include/linux/fs.h:766 [inline]
 [<ffffffff815a88e5>] do_last fs/namei.c:3312 [inline]
 [<ffffffff815a88e5>] path_openat+0xed5/0x3590 fs/namei.c:3534
 [<ffffffff815af267>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff81571a3d>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff81571d97>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff81571d97>] SyS_open fs/open.c:1085 [inline]
 [<ffffffff81571d97>] SYSC_creat fs/open.c:1110 [inline]
 [<ffffffff81571d97>] SyS_creat+0x27/0x30 fs/open.c:1108
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a00cd3>] 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: [<ffffffff81368a5c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81368a5c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff814282c8>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3682:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815dbb4c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3779:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839fee72>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82124562>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor4/12933:
 #0:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815987a1>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815987a1>] lookup_slow+0x141/0x470 fs/namei.c:1645
2 locks held by syz-executor4/12981:
 #0:  (sb_writers#17){.+.+.+}, at: [<ffffffff815e442f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#17){.+.+.+}, at: [<ffffffff815e442f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815a88e5>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815a88e5>] do_last fs/namei.c:3312 [inline]
 #1:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815a88e5>] path_openat+0xed5/0x3590 fs/namei.c:3534
1 lock held by syz-executor4/12984:
 #0:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815e535c>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815e535c>] lock_mount+0x8c/0x2c0 fs/namespace.c:2101
1 lock held by syz-executor4/12990:
 #0:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815987a1>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&sb->s_type->i_mutex_key#26){++++++}, at: [<ffffffff815987a1>] lookup_slow+0x141/0x470 fs/namei.c:1645

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.122-g54068d6 #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d857fd08 ffffffff81eb8829 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b9fa0 ffff8801d857fd40
 ffffffff81ec3b67 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb8829>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb8829>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ec3b67>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ec3afa>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810ba0a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81368ff4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81368ff4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368ff4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368ff4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119f38d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff83a00e9c>] 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 skipped: idling at pc 0xffffffff839ff8d6