INFO: task syz-executor.0:5842 blocked for more than 140 seconds.
      Not tainted 4.14.109+ #46
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D27528  5842   1845 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:572 [inline]
 rwsem_down_write_failed+0x3b1/0x760 kernel/locking/rwsem-xadd.c:601
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:56
 inode_lock include/linux/fs.h:715 [inline]
 ext4_file_write_iter+0x1fe/0xe40 fs/ext4/file.c:233
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:471 [inline]
 __vfs_write+0x401/0x5a0 fs/read_write.c:484
 vfs_write+0x17f/0x4d0 fs/read_write.c:546
 SYSC_write fs/read_write.c:593 [inline]
 SyS_write+0xc0/0x1a0 fs/read_write.c:585
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
INFO: task syz-executor.0:5901 blocked for more than 140 seconds.
      Not tainted 4.14.109+ #46
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29712  5901   1845 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:572 [inline]
 rwsem_down_write_failed+0x3b1/0x760 kernel/locking/rwsem-xadd.c:601
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:56
 inode_lock include/linux/fs.h:715 [inline]
 do_truncate2+0x10c/0x1e0 fs/open.c:61
 handle_truncate fs/namei.c:3039 [inline]
 do_last fs/namei.c:3464 [inline]
 path_openat+0x1208/0x2b70 fs/namei.c:3597
 do_filp_open+0x1a1/0x280 fs/namei.c:3631
 do_sys_open+0x2ca/0x590 fs/open.c:1071
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.?}, at: [<000000007282104f>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544
1 lock held by rsyslogd/1627:
 #0:  (&f->f_pos_lock){+.+.}, at: [<00000000014d9c08>] __fdget_pos+0xa6/0xc0 fs/file.c:768
2 locks held by getty/1755:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000b394e098>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000f3e9d621>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
3 locks held by syz-executor.0/5842:
 #0:  (&f->f_pos_lock){+.+.}, at: [<00000000014d9c08>] __fdget_pos+0xa6/0xc0 fs/file.c:768
 #1:  (sb_writers#4){.+.+}, at: [<00000000b0ba81da>] file_start_write include/linux/fs.h:2726 [inline]
 #1:  (sb_writers#4){.+.+}, at: [<00000000b0ba81da>] vfs_write+0x3d8/0x4d0 fs/read_write.c:545
 #2:  (&sb->s_type->i_mutex_key#9){++++}, at: [<00000000f9ddc125>] inode_lock include/linux/fs.h:715 [inline]
 #2:  (&sb->s_type->i_mutex_key#9){++++}, at: [<00000000f9ddc125>] ext4_file_write_iter+0x1fe/0xe40 fs/ext4/file.c:233
2 locks held by syz-executor.0/5901:
 #0:  (sb_writers#4){.+.+}, at: [<000000008f043ac2>] sb_start_write include/linux/fs.h:1545 [inline]
 #0:  (sb_writers#4){.+.+}, at: [<000000008f043ac2>] mnt_want_write+0x3a/0xb0 fs/namespace.c:387
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<00000000501e7789>] inode_lock include/linux/fs.h:715 [inline]
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<00000000501e7789>] do_truncate2+0x10c/0x1e0 fs/open.c:61

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.109+ #46
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff96c48bd2