netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
INFO: task syz-executor.0:2113 blocked for more than 140 seconds.
      Not tainted 4.9.192+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D25016  2113      1 0x00000004
 0000000000000087 ffff8801d426c740 0000000000000000 ffff8801db621000
 ffff8801d51b97c0 ffff8801db621018 ffff8801a99e7598 ffffffff8281ac3e
 ffffffff81bcd8bc ffff8801a99e75c8 00ffffff812055de ffff8801db6218f0
Call Trace:
 [<00000000f9bc889a>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<00000000b2faf2aa>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<000000007b6d56ec>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<000000007b6d56ec>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<00000000aac9b722>] fuse_lock_inode+0xad/0xe0 fs/fuse/inode.c:364
 [<00000000554a69c2>] fuse_lookup+0x89/0x3b0 fs/fuse/dir.c:406
 [<00000000dfbb4ae0>] lookup_slow+0x24b/0x480 fs/namei.c:1793
 [<00000000396abff2>] walk_component+0x71e/0xce0 fs/namei.c:1909
 [<00000000ea3a13c7>] link_path_walk+0x8b4/0x1210 fs/namei.c:2245
 [<0000000031d17686>] path_mountpoint+0x67/0x6d0 fs/namei.c:2821
 [<00000000e9be2e2a>] filename_mountpoint+0x17f/0x350 fs/namei.c:2842
 [<000000002a0b97ff>] user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2872
 [<0000000055db3020>] SYSC_umount fs/namespace.c:1722 [inline]
 [<0000000055db3020>] SyS_umount+0x136/0xd30 fs/namespace.c:1706
 [<00000000ad7a9dfe>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<0000000090a5ff5a>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<00000000b28cd717>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<00000000b28cd717>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<000000001704bdba>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
2 locks held by rs:main Q:Reg/1896:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<00000000bd317df9>] __fdget_pos+0xa8/0xd0 fs/file.c:782
 #1:  (sb_writers#4){.+.+.+}, at: [<0000000014b3c382>] file_start_write include/linux/fs.h:2646 [inline]
 #1:  (sb_writers#4){.+.+.+}, at: [<0000000014b3c382>] vfs_write+0x3e9/0x520 fs/read_write.c:558
2 locks held by getty/2026:
 #0:  (&tty->ldisc_sem){++++++}, at: [<00000000cdf3a04b>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<000000008bd3fba3>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.0/2113:
 #0:  (&type->i_mutex_dir_key#7){++++++}, at: [<00000000c3cb47cd>] inode_lock_shared include/linux/fs.h:781 [inline]
 #0:  (&type->i_mutex_dir_key#7){++++++}, at: [<00000000c3cb47cd>] lookup_slow+0x160/0x480 fs/namei.c:1770
 #1:  (&fi->mutex){+.+.+.}, at: [<00000000aac9b722>] fuse_lock_inode+0xad/0xe0 fs/fuse/inode.c:364
2 locks held by syz-executor.0/8910:
 #0:  (&type->i_mutex_dir_key#7){++++++}, at: [<00000000c3cb47cd>] inode_lock_shared include/linux/fs.h:781 [inline]
 #0:  (&type->i_mutex_dir_key#7){++++++}, at: [<00000000c3cb47cd>] lookup_slow+0x160/0x480 fs/namei.c:1770
 #1:  (&fi->mutex){+.+.+.}, at: [<00000000aac9b722>] fuse_lock_inode+0xad/0xe0 fs/fuse/inode.c:364

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.192+ #0
 ffff8801d98d7cc8 ffffffff81b67081 0000000000000001 0000000000000000
 0000000000000001 ffffffff81099e01 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b7231c 0000000000000001 0000000000000000 0000000000000001
Call Trace:
 [<000000003814617d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<000000003814617d>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<000000004d59a290>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<00000000af16f325>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<00000000c556f244>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<000000009820e49d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<000000009820e49d>] check_hung_task kernel/hung_task.c:126 [inline]
 [<000000009820e49d>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
 [<000000009820e49d>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
 [<000000008df1ba81>] kthread+0x278/0x310 kernel/kthread.c:211
 [<00000000a9ab1d1a>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff82829d91