Been there, done that. Ok, a colleague did it, sbkut 30 years ago ;-)

IIRC resetting the machine and forcing it to single boot was the solution.

not op but we recently wanted to mount nfs and the sysadmin was adamant we use automounter[0] instead of fstab because if the nfs mount is not available it can hang the kernel.

Not sure if it is true or just sysadmin lore but was interesting enough to learn about a alternative.

[0]: https://linux.die.net/man/8/automount

Oh this can definitely happen, had it occur on my system till I started using nofail as a mount option.