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Date:   Mon, 3 Jul 2023 12:41:01 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Samuel Thibault <samuel.thibault@ens-lyon.org>,
        Kees Cook <kees@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Simon Brand <simon.brand@postadigitale.de>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
        Dave@mielke.cc
Subject: Re: [PATCH v3 2/2] tty: Allow TIOCSTI to be disabled
Message-ID: <202307031240.0B8B07ECD@keescook>
References: <20221022182828.give.717-kees@kernel.org>
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On Sun, Jul 02, 2023 at 02:00:23AM +0200, Samuel Thibault wrote:
> Kees Cook, le mer. 28 juin 2023 09:32:20 -0700, a ecrit:
> > On Wed, Jun 28, 2023 at 08:07:16AM +0200, Samuel Thibault wrote:
> > > Kees Cook, le mar. 27 juin 2023 19:48:45 -0700, a ecrit:
> > > > > Really, this a serious regression for the people affected by this.
> > > > 
> > > > Can you send a patch adding a CAP_SYS_ADMIN exception?
> > > 
> > > Sure!
> > 
> > Thanks! (And be sure to use file->f_cred for the check[1], not "current",
> > that way brltty can open the tty and drop caps and still do the ioctl.)
> 
> Actually brltty re-opens the various tty[1-6] consoles when the users
> switches, so I kept just testing capable(CAP_SYS_ADMIN).

Well that's frustrating. :P

-- 
Kees Cook