Keybase 6.2.4 (fs?) blocks. df, nautilus, even firefox file browsers won't open. Seems new.

```
$ dmesg
[ 484.594841] INFO: task keybase:18831 blocked for more than 241 seconds.
[ 484.594855] Tainted: P O 6.2.0-39-generic #40~22.04.1-Ubuntu
[ 484.594859] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 484.594862] task:keybase state:D stack:0 pid:18831 ppid:17624 flags:0x00000006
[ 484.594871] Call Trace:
[ 484.594875]
[ 484.594881] __schedule+0x2b7/0x5f0
[ 484.594893] schedule+0x68/0x110
[ 484.594898] schedule_preempt_disabled+0x15/0x30
[ 484.594902] rwsem_down_read_slowpath+0x243/0x4d0
[ 484.594909] ? try_to_unlazy+0x60/0xe0
[ 484.594918] down_read+0x4a/0xc0
[ 484.594924] walk_component+0x113/0x190
[ 484.594932] path_lookupat+0x6e/0x1c0
[ 484.594936] filename_lookup+0xcf/0x1e0
[ 484.594942] ? check_heap_object+0x185/0x1d0
[ 484.594951] ? __check_object_size.part.0+0x72/0x150
[ 484.594958] vfs_statx+0x91/0x170
[ 484.594966] vfs_fstatat+0x59/0x80
[ 484.594972] __do_sys_newfstatat+0x2b/0x70
[ 484.594980] ? ksys_read+0xda/0xf0
[ 484.594986] ? exit_to_user_mode_prepare+0x3b/0xd0
[ 484.594992] __x64_sys_newfstatat+0x1c/0x30
[ 484.594999] do_syscall_64+0x59/0x90
[ 484.595006] ? handle_mm_fault+0x119/0x330
[ 484.595010] ? lock_mm_and_find_vma+0x44/0x250
[ 484.595018] ? do_user_addr_fault+0x1d0/0x640
[ 484.595023] ? exit_to_user_mode_prepare+0x3b/0xd0
[ 484.595027] ? irqentry_exit_to_user_mode+0x17/0x20
[ 484.595034] ? irqentry_exit+0x43/0x50
[ 484.595039] ? exc_page_fault+0x92/0x1b0
[ 484.595046] entry_SYSCALL_64_after_hwframe+0x73/0xdd
[ 484.595052] RIP: 0033:0x56014c8d172e
[ 484.595058] RSP: 002b:000000c002f39a68 EFLAGS: 00000202 ORIG_RAX: 0000000000000106
[ 484.595064] RAX: ffffffffffffffda RBX: ffffffffffffff9c RCX: 000056014c8d172e
[ 484.595067] RDX: 000000c005f517c8 RSI: 000000c005f62270 RDI: ffffffffffffff9c
[ 484.595070] RBP: 000000c002f39aa8 R08: 0000000000000000 R09: 0000000000000000
[ 484.595073] R10: 0000000000000100 R11: 0000000000000202 R12: 0000000000000000
[ 484.595076] R13: 000000c00008ac00 R14: 000000c004cb1a00 R15: 000000000000001a
[ 484.595083]
```
This just repeats. It never seems to work.
```
$ apt list --installed keybase
Listing... Done
keybase/unknown,now 6.2.4-20240101011938.ae7e4a1c15 amd64 [installed]
```

```
$ strace df
execve("/usr/bin/df", ["df"], 0x7ffc41c3f840 /* 58 vars */) = 0
... normal startup stuff ...
futex(0x7f53678d0a6c, FUTEX_WAKE_PRIVATE, 2147483647) = 0
newfstatat(AT_FDCWD, "/run", {st_mode=S_IFDIR|0755, st_size=1200, ...}, 0) = 0
.... etc etc lots of newfsatat calls
newfstatat(AT_FDCWD, "/keybase",
```
Blocked there indefinitely.

Can't open firefox file browser to upload / download files. Can't open fire system browser from desktop by clicking on app. Can't even `ls /`

Start by reproducing the hang at the /keybase mount and review the supplied dmesg and strace output, especially the blocked newfstatat call. Done means filesystem operations such as df, ls, and browser file dialogs no longer block indefinitely on /keybase.

Written by the indexing model from the issue text.