[PATCH] KEYS: fix overflow in keyctl_pkey_params_get_2()

[Jarkko Sakkinen]

On Sun, May 31, 2026 at 05:49:13AM +0300, Jarkko Sakkinen wrote:
> The length for the internal output buffer is calculated incorrectly, which
> can result overflow when a too small buffer is provided.
> 
> Fix the bug by allocating internal output with the size of the maximum
> length of the cryptographic primitive instead of caller provided size.
> 
> Cc: stable at vger.kernel.org # v4.20+
> Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
> Reported-by: Alessandro Grupp <ale.grpp at gmail.com>
> Signed-off-by: Jarkko Sakkinen <jarkko at kernel.org>

Should be available in -next within a day or along the lines so please
be quick with tags/feedback. I'll forward a PR as soon as all is good.

BR, Jarkko