From: Daniel Micay <danielmicay@gmail.com>
To: Alan Cox <gnomes@lxorguk.ukuu.org.uk>, Matt Brown <matt@nmatt.com>
Cc: serge@hallyn.com, gregkh@linuxfoundation.org, jslaby@suse.com,
akpm@linux-foundation.org, jannh@google.com,
keescook@chromium.org, jmorris@namei.org,
kernel-hardening@lists.openwall.com,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [kernel-hardening] Re: [PATCH v6 0/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN
Date: Wed, 10 May 2017 17:02:14 -0400 [thread overview]
Message-ID: <1494450134.28559.2.camel@gmail.com> (raw)
In-Reply-To: <20170510212920.7f6bc5e6@alans-desktop>
On Wed, 2017-05-10 at 21:29 +0100, Alan Cox wrote:
>
> In addition your change to allow it to be used by root in the guest
> completely invalidates any protection you have because I can push
>
> "rm -rf /\n"
>
> as root in my namespace and exit
>
> The tty buffers are not flushed across the context change so the shell
> you return to gets the input and oh dear....
>
> Alan
I might be missing something, but it looks like the patch tracks where
the tty was created and only allows this with CAP_SYS_ADMIN in the ns
where the tty came from.
WARNING: multiple messages have this Message-ID (diff)
From: danielmicay@gmail.com (Daniel Micay)
To: linux-security-module@vger.kernel.org
Subject: [kernel-hardening] Re: [PATCH v6 0/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN
Date: Wed, 10 May 2017 17:02:14 -0400 [thread overview]
Message-ID: <1494450134.28559.2.camel@gmail.com> (raw)
In-Reply-To: <20170510212920.7f6bc5e6@alans-desktop>
On Wed, 2017-05-10 at 21:29 +0100, Alan Cox wrote:
>
> In addition your change to allow it to be used by root in the guest
> completely invalidates any protection you have because I can push
>
> "rm -rf /\n"
>
> as root in my namespace and exit
>
> The tty buffers are not flushed across the context change so the shell
> you return to gets the input and oh dear....
>
> Alan
I might be missing something, but it looks like the patch tracks where
the tty was created and only allows this with CAP_SYS_ADMIN in the ns
where the tty came from.
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next prev parent reply other threads:[~2017-05-10 21:02 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-05 23:20 [kernel-hardening] [PATCH v6 0/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN Matt Brown
2017-05-05 23:20 ` Matt Brown
2017-05-05 23:20 ` Matt Brown
2017-05-05 23:20 ` [kernel-hardening] [PATCH v6 1/2] security: tty: Add owner user namespace to tty_struct Matt Brown
2017-05-05 23:20 ` Matt Brown
2017-05-05 23:20 ` Matt Brown
2017-05-05 23:20 ` [kernel-hardening] [PATCH v6 2/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN Matt Brown
2017-05-05 23:20 ` Matt Brown
2017-05-05 23:20 ` Matt Brown
2017-05-18 13:31 ` [kernel-hardening] " Greg KH
2017-05-18 13:31 ` Greg KH
2017-05-18 13:31 ` Greg KH
2017-05-19 4:51 ` [kernel-hardening] " Matt Brown
2017-05-19 4:51 ` Matt Brown
2017-05-19 4:51 ` Matt Brown
2017-05-10 20:29 ` [kernel-hardening] Re: [PATCH v6 0/2] " Alan Cox
2017-05-10 20:29 ` Alan Cox
2017-05-10 20:29 ` Alan Cox
2017-05-10 21:02 ` Daniel Micay [this message]
2017-05-10 21:02 ` [kernel-hardening] " Daniel Micay
2017-05-13 19:52 ` Matt Brown
2017-05-13 19:52 ` Matt Brown
2017-05-13 19:52 ` Matt Brown
2017-05-15 4:45 ` [kernel-hardening] " Nicolas Belouin
2017-05-15 20:57 ` Alan Cox
2017-05-15 20:57 ` Alan Cox
2017-05-15 20:57 ` Alan Cox
2017-05-15 23:10 ` [kernel-hardening] " Peter Dolding
2017-05-15 23:10 ` Peter Dolding
2017-05-15 23:10 ` Peter Dolding
2017-05-16 4:15 ` [kernel-hardening] " Matt Brown
2017-05-16 4:15 ` Matt Brown
2017-05-16 4:15 ` Matt Brown
2017-05-16 9:01 ` [kernel-hardening] " Peter Dolding
2017-05-16 9:01 ` Peter Dolding
2017-05-16 9:01 ` Peter Dolding
2017-05-16 12:22 ` [kernel-hardening] " Matt Brown
2017-05-16 12:22 ` Matt Brown
2017-05-16 12:22 ` Matt Brown
2017-05-16 14:28 ` [kernel-hardening] " Kees Cook
2017-05-16 14:28 ` Kees Cook
2017-05-16 14:28 ` Kees Cook
2017-05-16 15:48 ` [kernel-hardening] " Serge E. Hallyn
2017-05-16 15:48 ` Serge E. Hallyn
2017-05-16 22:05 ` Peter Dolding
2017-05-16 22:05 ` Peter Dolding
2017-05-16 21:43 ` Peter Dolding
2017-05-16 21:43 ` Peter Dolding
2017-05-16 21:43 ` Peter Dolding
2017-05-16 21:54 ` [kernel-hardening] " Matt Brown
2017-05-16 21:54 ` Matt Brown
2017-05-16 21:54 ` Matt Brown
2017-05-17 16:41 ` [kernel-hardening] " Alan Cox
2017-05-17 16:41 ` Alan Cox
2017-05-17 16:41 ` Alan Cox
2017-05-17 18:25 ` [kernel-hardening] " Daniel Micay
2017-05-17 18:25 ` Daniel Micay
2017-05-17 23:04 ` Boris Lukashev
2017-05-18 3:18 ` Kees Cook
2017-05-18 3:18 ` Kees Cook
2017-05-19 2:48 ` Peter Dolding
2017-05-19 2:48 ` Peter Dolding
2017-05-19 4:08 ` Boris Lukashev
2017-05-19 14:33 ` Serge E. Hallyn
2017-05-19 14:33 ` Serge E. Hallyn
2017-05-29 10:42 ` Peter Dolding
2017-05-29 10:42 ` Peter Dolding
2017-05-30 15:52 ` Serge E. Hallyn
2017-05-30 15:52 ` Serge E. Hallyn
2017-05-30 21:52 ` Alan Cox
2017-05-30 21:52 ` Alan Cox
2017-05-31 11:27 ` Peter Dolding
2017-05-31 11:27 ` Peter Dolding
2017-05-31 14:36 ` Alan Cox
2017-05-31 14:36 ` Alan Cox
2017-05-31 15:32 ` Serge E. Hallyn
2017-05-31 15:32 ` Serge E. Hallyn
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