memory leak in autofs

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2022/06/09 08:01	14m	mudongliangabcd@gmail.com		https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git --	report log

BUG: memory leak
unreferenced object 0xffff88810c87a400 (size 96):
  comm "syz-executor416", pid 3611, jiffies 4294957452 (age 13.060s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 08 a4 87 0c 81 88 ff ff  ................
    08 a4 87 0c 81 88 ff ff 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81bae93e>] kmalloc include/linux/slab.h:581 [inline]
    [<ffffffff81bae93e>] autofs_wait+0x3fe/0x9a0 fs/autofs/waitq.c:378
    [<ffffffff81bafbf7>] autofs_do_expire_multi+0xa7/0x3e0 fs/autofs/expire.c:593
    [<ffffffff81baff83>] autofs_expire_multi+0x53/0x80 fs/autofs/expire.c:619
    [<ffffffff81bad942>] autofs_root_ioctl_unlocked+0x322/0x3b0 fs/autofs/root.c:905
    [<ffffffff81bada65>] autofs_root_ioctl+0x25/0x30 fs/autofs/root.c:918
    [<ffffffff815e422c>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff815e422c>] __do_sys_ioctl fs/ioctl.c:870 [inline]
    [<ffffffff815e422c>] __se_sys_ioctl fs/ioctl.c:856 [inline]
    [<ffffffff815e422c>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:856
    [<ffffffff84565f05>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84565f05>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae