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From: Gerd Hoffmann <kraxel@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	Peter Maydell <peter.maydell@linaro.org>,
	Prasad J Pandit <ppandit@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>, qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH 0/1] display/bochs: fix pcie support (qemu security issue)
Date: Mon, 12 Aug 2019 08:52:20 +0200	[thread overview]
Message-ID: <20190812065221.20907-1-kraxel@redhat.com> (raw)

Just found while investigating
  https://bugzilla.redhat.com/show_bug.cgi?id=1707118

Found PCIe extended config space filled with random crap due to
allocation being too small (conventional pci config space only).

PCI(e) config space is guest writable.  Writes are limited by
write mask (which probably is also filled with random stuff),
so the guest can only flip enabled bits.  But I suspect it
still might be exploitable, so rather serious because it might
be a host escape for the guest.  On the other hand the device
is probably not yet in widespread use.

Migitation: use "-device bochs-display" as conventional pci
device only.

Note: qemu 4.1 release is planned for tomorrow.

Gerd Hoffmann (1):
  display/bochs: fix pcie support

 hw/display/bochs-display.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

-- 
2.18.1



             reply	other threads:[~2019-08-12  6:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-12  6:52 Gerd Hoffmann [this message]
2019-08-12  6:52 ` [Qemu-devel] [PATCH 1/1] display/bochs: fix pcie support Gerd Hoffmann
2019-08-12 12:59   ` Alex Williamson
2019-08-12 12:45 ` [Qemu-devel] [PATCH 0/1] display/bochs: fix pcie support (qemu security issue) Paolo Bonzini
2019-08-12 12:51   ` Philippe Mathieu-Daudé
2019-08-12 13:39     ` Peter Maydell
2019-08-12 14:15       ` Philippe Mathieu-Daudé
2019-08-12 15:35       ` Alex Williamson
2019-08-12 15:38         ` Peter Maydell
2019-08-12 15:48           ` Alex Williamson
2019-08-12 16:34             ` Peter Maydell

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