Re: [PATCH v4 1/3] KEYS: Expand key->{datalen,quotalen} to unsigned int

[Jarkko Sakkinen <jarkko@kernel.org>]

On Tue, Oct 20, 2026 at 08:43:19PM +0300, Jarkko Sakkinen wrote:
> In key_alloc() and key_payload_reserve(), key->quotalen and key->datalen
> can receive values larger than USHRT_MAX.
> 
> Example:
> 
>   keyctl new_session >/dev/null
>   owner=$(keyctl newring owner @s)
>   keeper=$(keyctl newring keeper @s)
> 
>   for ((i=0; i<16384; i++)); do
>       key=$(keyctl add user "k$i" x "$keeper")
>       keyctl link "$key" "$owner"
>   done
> 
>   awk -v uid="$(id -u):" '$1 == uid {print $NF}' /proc/key-users
>   keyctl clear "$owner"
>   awk -v uid="$(id -u):" '$1 == uid {print $NF}' /proc/key-users
> 
> Because key->datalen wraps around 65535, the quota refunded upon clearing
> is truncated, causing quota bytes to leak in /proc/key-users.
> 
> Change the types of key->datalen and key->quotalen from unsigned short to
> unsigned int so that they can carry the full payload length without
> truncation.
> 
> Cc: stable@vger.kernel.org
> Assisted-by: LLM
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Reviewed-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

For any kernel patches I've missed all Sashiko reviews so far and have
not taken the feedback into account in anything.

There is two issues:

1. I was not subscribed to linux-security-module. I could be and have
   been but probably when I've changed my list subscriptions at some
   point otherwise, I happened not to be.
2. Even if I was subscribed to linux-security-module, at least I'd
   like to get reviews Cc'd that concern my patches or patches
   sent to me.

Now that Eric pointed out Sashiko review I was able to look up this
via web browser:

https://lore.kernel.org/linux-security-module/20261020174325.2229448-1-jarkko@kernel.org/T/#mccc5900222fdad9d790be343fcec2a32540ed2fb

This is somewhat inconvenient though that it responds like that, and
not to the review thread.

Not actually sure how do you write a Sieve filter that automates
relevant-to-me Sashiko emails going into some specific folder but
I'm sure that is somehow possible. I guess I'll start by subscribing
to linux-security-module.

Br, Jarkko