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From: gnomes@lxorguk.ukuu.org.uk (Alan Cox)
To: linux-security-module@vger.kernel.org
Subject: [kernel-hardening] Re: [PATCH v7 2/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN
Date: Wed, 31 May 2017 00:56:33 +0100	[thread overview]
Message-ID: <20170531005633.484a2e14@alans-desktop> (raw)
In-Reply-To: <3bd4ff7b-6f7d-52b0-03f6-026bac79f11f@nmatt.com>

> This is my point. Apps will continue to shoot themselves in the foot. Of course
> the correct response to one of these vulns is to not pass ttys across a
> security boundary. We have an opportunity here to reduce the impact of this bug
> class at the kernel level. 

Not really.

If you pass me your console for example I can mmap your framebuffer and
spy on you all day. Or I could reprogram your fonts, your keyboard, your
video mode, or use set and paste selection to write stuff. If you are
using X and you can't get tty handles right you'll no doubt pass me a
copy of your X file descriptor in which case I own your display, your
keyboard and your mouse and I don't need to use TIOCSTI there either.

There are so many different attacks based upon that screwup that the
kernel cannot defend against them. You aren't exactly reducing the impact.

Alan
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  reply	other threads:[~2017-05-30 23:56 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-29 21:37 [PATCH v7 0/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN Matt Brown
2017-05-29 21:37 ` [PATCH v7 1/2] security: tty: Add owner user namespace to tty_struct Matt Brown
2017-05-29 21:38 ` [PATCH v7 2/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN Matt Brown
2017-05-29 22:26   ` Alan Cox
2017-05-29 23:51     ` [kernel-hardening] " Boris Lukashev
2017-05-30  0:27       ` Casey Schaufler
2017-05-30  2:00         ` Matt Brown
2017-05-30  2:46           ` Casey Schaufler
2017-05-30  3:18             ` Matt Brown
2017-05-30 12:24               ` Alan Cox
2017-05-30 16:28                 ` Matt Brown
2017-05-30 16:44                   ` Daniel Micay
2017-05-30 18:32                   ` Stephen Smalley
2017-05-30 18:44                     ` Nick Kralevich
2017-05-30 18:57                       ` Matt Brown
2017-05-30 20:22                         ` Daniel Micay
2017-05-30 23:00                           ` Matt Brown
2017-05-30 23:40                             ` Daniel Micay
2017-05-30 23:59                               ` Matt Brown
2017-05-30 22:51                   ` Alan Cox
2017-05-30 23:19                     ` Matt Brown
2017-05-30 23:56                       ` Alan Cox [this message]
2017-06-01  2:35                         ` Kees Cook
2017-06-01 13:08                           ` Alan Cox
2017-06-01 17:18                             ` Serge E. Hallyn
2017-06-01 21:26                               ` Alan Cox
2017-06-01 18:58                             ` Kees Cook
2017-06-01 21:24                               ` Alan Cox
2017-06-02 14:46                                 ` Matt Brown
2017-06-02 15:36                                   ` Serge E. Hallyn
2017-06-02 16:02                                     ` Matt Brown
2017-06-02 16:57                                       ` Serge E. Hallyn
2017-06-02 17:32                                         ` Matt Brown
2017-06-02 18:18                                           ` Serge E. Hallyn
2017-06-02 19:22                                             ` Matt Brown
2017-06-02 19:25                                               ` Kees Cook
2017-06-02 19:26                                                 ` Matt Brown
2017-06-02 20:05                                       ` Alan Cox
2017-06-02 20:11                                         ` Nick Kralevich
2017-06-02 20:46                                         ` Matt Brown
2017-06-03 22:00                                           ` Alan Cox
2017-06-03 22:22                                             ` Matt Brown
2017-06-04  3:37                                               ` Peter Dolding
2017-05-30 15:20               ` Casey Schaufler
2017-05-30 16:09                 ` Matt Brown
2017-06-04  6:29         ` Boris Lukashev
2017-05-31  2:48       ` James Morris
2017-05-31  4:10         ` Matt Brown
2017-05-30  0:15     ` Matt Brown

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