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From: Jean-Francois Moine <moinejf@free.fr>
To: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tty vt: fix character insertion overflow
Date: Mon, 25 Feb 2013 09:50:18 +0100	[thread overview]
Message-ID: <20130225095018.387b165e@armhf> (raw)
In-Reply-To: <alpine.LFD.2.03.1302242001070.2213@syhkavp.arg>

On Sun, 24 Feb 2013 20:06:09 -0500 (EST)
Nicolas Pitre <nicolas.pitre@linaro.org> wrote:

> Commit 81732c3b2f (tty vt: Fix line garbage in virtual console on
> command line edition) broke insert_char() in multiple ways.  Then
> commit b1a925f44a (tty vt: Fix a regression in command line edition)
> partially fixed it.  However, the buffer being moved is still too large
> and overflowing beyond the end of the current line, corrupting existing
> characters on the next line.

and

> One detail I didn't mention explicitly is that the cursor can be moved 
> to the last screen line, and then the sequence ESC [ <n> @ is all that 
> is needed to shovel 2*n bytes from that bottom screen line into adjacent 
> memory which could potentially be exploited in some way.

You are right, this bug is critical. Sorry.

Acked-by: Jean-François Moine <moinejf@free.fr>

-- 
Ken ar c'hentañ	|	      ** Breizh ha Linux atav! **
Jef		|		http://moinejf.free.fr/

      reply	other threads:[~2013-02-25  8:50 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-25  1:06 [PATCH] tty vt: fix character insertion overflow Nicolas Pitre
2013-02-25  8:50 ` Jean-Francois Moine [this message]

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