Re: [hackers] [slock] Avoid ctype(3) abuses || Leonardo Taccari

From: Laslo Hunhold <dev_AT_frign.de>
Date: Tue, 28 Jul 2026 09:18:07 +0200

On Mon, 27 Jul 2026 23:55:03 +0200 (CEST)
git_AT_suckless.org wrote:

Hello,

what a great catch!

With best regards

Laslo

> Valid argument of ctype(3) functions must be either EOF or
> non-negative value within the range representable as unsigned char.
> Invalid values leads to undefined behavior.
>
> Cast all such uses to avoid that.
>
> At least in NetBSD 11 ctype(3) abuses will always crash and permit
> to break slock screen locking.
Received on Tue Jul 28 2026 - 09:18:07 CEST