[GIT PULL] fscrypt fix for v6.3-rc4

[Linus Torvalds]

On Mon, Mar 20, 2023 at 1:56 PM Eric Biggers <ebiggers at kernel.org> wrote:
>
>       fscrypt: check for NULL keyring in fscrypt_put_master_key_activeref()

Side note: please just use WARN_ON_ONCE() for things like this, not WARN_ON.

If it's triggerable, it should be triggered only once rather than
flood the logs and possibly cause a DoS.

And if it's not triggerable, the "ONCE" doesn't matter.

I note that fscypt in general seems to be *way* too happy with
WARN_ON() as some kind of debugging aid.

It's not good in general (printf for debugging is wonderful, but
shouldn't be left in the sources to rot for all eternity), but it's
particularly not good in that form.

              Linus