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From: Kees Cook <keescook@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>,
	Jiri Slaby <jirislaby@kernel.org>,
	Simon Brand <simon.brand@postadigitale.de>,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH v3 0/2] tty: Allow TIOCSTI to be disabled
Date: Sat, 22 Oct 2022 11:29:47 -0700	[thread overview]
Message-ID: <20221022182828.give.717-kees@kernel.org> (raw)

Hi,

v3: make sysctl a bool (Jiri)
v2: https://lore.kernel.org/lkml/20221015064222.gonna.435-kees@kernel.org
v1: https://lore.kernel.org/lkml/20221015041352.never.966-kees@kernel.org/

This is so very long over-due. We just need to do this and put an end
to this legacy operation.

Repeating the commit log from patch 2:

    TIOCSTI continues its long history of being used in privilege escalation
    attacks[1]. Prior attempts to provide a mechanism to disable this have
    devolved into discussions around creating full-blown LSMs to provide
    arbitrary ioctl filtering, which is hugely over-engineered -- only
    TIOCSTI is being used this way. 3 years ago OpenBSD entirely removed
    TIOCSTI[2], Android has had it filtered for longer[3], and the tools that
    had historically used TIOCSTI either do not need it, are not commonly
    built with it, or have had its use removed.

    Provide a simple CONFIG and global sysctl to disable this for the system
    builders who have wanted this functionality for literally decades now,
    much like the ldisc_autoload CONFIG and sysctl.

    [1] https://lore.kernel.org/linux-hardening/Y0m9l52AKmw6Yxi1@hostpad
    [2] https://undeadly.org/cgi?action=article;sid=20170701132619
    [3] https://lore.kernel.org/lkml/CAFJ0LnFGRuEEn1tCLhoki8ZyWrKfktbF+rwwN7WzyC_kBFoQVA@mail.gmail.com/

Thanks,

-Kees


Kees Cook (2):
  tty: Move sysctl setup into "core" tty logic
  tty: Allow TIOCSTI to be disabled

 drivers/tty/Kconfig     | 19 +++++++++++++++++
 drivers/tty/tty.h       |  2 +-
 drivers/tty/tty_io.c    | 45 +++++++++++++++++++++++++++++++++++++++--
 drivers/tty/tty_ldisc.c | 38 +---------------------------------
 4 files changed, 64 insertions(+), 40 deletions(-)

-- 
2.34.1


             reply	other threads:[~2022-10-22 18:30 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-22 18:29 Kees Cook [this message]
2022-10-22 18:29 ` [PATCH v3 1/2] tty: Move sysctl setup into "core" tty logic Kees Cook
2022-10-22 18:29 ` [PATCH v3 2/2] tty: Allow TIOCSTI to be disabled Kees Cook
2022-11-15 13:17   ` Geert Uytterhoeven
2022-12-27 23:40   ` Samuel Thibault
2022-12-27 23:41     ` Samuel Thibault
2022-12-28  3:32     ` Kees Cook
2022-12-28 20:57       ` Samuel Thibault
2023-06-25 15:56         ` Samuel Thibault
2023-06-27 21:50           ` Samuel Thibault
2023-06-28  0:21             ` Paul Moore
2023-06-28  2:48           ` Kees Cook
2023-06-28  6:07             ` Samuel Thibault
2023-06-28 16:32               ` Kees Cook
2023-07-02  0:00                 ` Samuel Thibault
2023-07-03 19:41                   ` Kees Cook
2023-06-29 13:23               ` David Laight
2023-06-29 13:32                 ` Samuel Thibault
2022-11-02  2:15 ` [PATCH v3 0/2] " Kees Cook
2022-11-02  2:29   ` Greg Kroah-Hartman
2022-11-02  2:46     ` Kees Cook

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