syzbot

INFO: task syz-executor.0:23887 blocked for more than 140 seconds.
      Not tainted 4.14.112+ #57
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D30176 23887   1840 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]
 vfs_setxattr+0x89/0xe0 fs/xattr.c:219
 setxattr+0x1bc/0x330 fs/xattr.c:453
 path_setxattr+0x138/0x150 fs/xattr.c:472
 SYSC_lsetxattr fs/xattr.c:494 [inline]
 SyS_lsetxattr+0x33/0x40 fs/xattr.c:490
 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: [<000000007dbd6acf>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544
2 locks held by getty/1748:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000fe2cbad5>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000004d05e1fd>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.0/23887:
 #0:  (sb_writers#4){.+.+}, at: [<00000000acdbf830>] sb_start_write include/linux/fs.h:1545 [inline]
 #0:  (sb_writers#4){.+.+}, at: [<00000000acdbf830>] mnt_want_write+0x3a/0xb0 fs/namespace.c:387
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<0000000036ad98a4>] inode_lock include/linux/fs.h:715 [inline]
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<0000000036ad98a4>] vfs_setxattr+0x89/0xe0 fs/xattr.c:219

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