Date: Wed, 13 Nov 2002 11:38:33 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: hackers@FreeBSD.ORG Subject: Re: tty/pty devices not safe in jail? Message-ID: <200211131938.gADJcX1X091590@apollo.backplane.com> References: <98061.1037215858@critter.freebsd.dk>
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:In message <200211131927.gADJRxP8085877@apollo.backplane.com>, Matthew Dillon w
:rites:
:> Hmm. While tracking down a null mount issue I think I might have
:> come across a potentially serious problem with jail. It seems to
:> me that it would be possible for someone inside a jailed environment
:> to 'steal' pty's, tty's, or the tty side of a pty that is being
:> used from within other jails or by processes outside the jail. Has
:> this ever come up before?
:
:There has always been code in kern/tty_pty.c which makes sure that the
:master and slave have the same prison:
:
: } else if (pti->pt_prison != td->td_ucred->cr_prison) {
: return (EBUSY);
:
:
:--
:Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
:phk@FreeBSD.ORG | TCP/IP since RFC 956
Ah, excellent. Is there a limit inside the prison so a jail cannot
exhaust all available ptys?
-Matt
Matthew Dillon
<dillon@backplane.com>
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