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From: Blue Swirl <blauwirbel@gmail.com>
To: anton.kochkov@gmail.com
Cc: qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] QEMU-KVM and hardened (GRSEC/PaX) kernel
Date: Tue, 19 Apr 2011 22:24:31 +0300	[thread overview]
Message-ID: <BANLkTim1a4EspaJk-rQhBCz-eRmKTM5KdA@mail.gmail.com> (raw)
In-Reply-To: <BANLkTi==x5GF+BC4q=fSVvYLE_XY=SvxTw@mail.gmail.com>

2011/4/17 Антон Кочков <anton.kochkov@gmail.com>:
> Good day!
> I'm trying to make working qemu-kvm with hardened gentoo on hardened kernel.
> When i'm using CONFIG_PAX_KERNPAGEXEC and CONFIG_PAX_MEM_UNDEREF qemu just start
> and go to infinite loop and take 100% of one of my CPU core. adn it
> even can't be killed.
> Also it is dont give answer for qemu monitor/remote gdb.
> When I'm changed these two values as disabled, qemu-kvm now start, and
> stop (i mean qemu monitor show that virtual machine is running, but no
> any activity/output). Also it's load about 0%.
> See details in bug http://bugs.gentoo.org/show_bug.cgi?id=363713

Given this description
http://grsecurity.net/~spender/uderef.txt
I'd say the problem is PaX vs. KVM (kernel module part of it). UDEREF
should be overridden for the process in question, which obviously
defeats security. Maybe CONFIG_GRKERNSEC_HARDENED_VIRTUALIZATION
suggested in the bug thread already does this, I don't know. It's not
possible to virtualize for example guests using self-modifying code if
the kernel protections are in the way. The alternative is to use only
guests, which never violate W^X, if they exist.

  reply	other threads:[~2011-04-19 19:24 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-16 22:45 [Qemu-devel] QEMU-KVM and hardened (GRSEC/PaX) kernel Антон Кочков
2011-04-19 19:24 ` Blue Swirl [this message]
2011-04-20  1:16   ` Антон Кочков
2011-04-20 14:29 ` Avi Kivity
2011-04-20 16:47   ` Антон Кочков
2011-04-21  8:03     ` Avi Kivity

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