From: Alasdair G Kergon <agk@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, security@kernel.org,
pmatouse@redhat.com, agk@redhat.com, jbottomley@parallels.com,
mchristi@redhat.com, msnitzer@redhat.com
Subject: Re: [PATCH 2/3] block: fail SCSI passthrough ioctls on partition devices
Date: Thu, 22 Dec 2011 23:48:30 +0000 [thread overview]
Message-ID: <20111222234830.GC31021@agk-dp.fab.redhat.com> (raw)
In-Reply-To: <CA+55aFw+ipBQFTj9SbNjE1KkS+xNpY7RdF1emSf7WrzavyReqA@mail.gmail.com>
On Thu, Dec 22, 2011 at 02:25:56PM -0800, Linus Torvalds wrote:
> I don't *think* anybody does something as crazy as giving actual block
> device ownership to people,
That can happen when running virtual machines backed by logical volumes.
Say I am running a server that offers virtual machines to different
people, and I allow those people to have root access within their own
guest, but, naturally, I don't give them any access to other people's
guests.
I pool my disks on the server into a Volume Group and create one simple
Logical Volume per guest VM to hold its filesystem.
Due to this bug, a root user inside one guest VM can see and modify the
contents of other VMs that don't belong to them (and in some situations
perhaps even take control of the host machine by modifying the host's
LVM metadata).
Alasdair
next prev parent reply other threads:[~2011-12-22 23:48 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-22 18:02 [PATCH 0/3] possible privilege escalation via SG_IO ioctl (CVE-2011-4127) Paolo Bonzini
2011-12-22 18:02 ` [PATCH 1/3] block: add and use scsi_blk_cmd_ioctl Paolo Bonzini
2011-12-22 18:02 ` [PATCH 2/3] block: fail SCSI passthrough ioctls on partition devices Paolo Bonzini
2011-12-22 18:37 ` Linus Torvalds
2011-12-22 19:11 ` Willy Tarreau
2011-12-22 19:18 ` Paolo Bonzini
2011-12-22 19:44 ` Linus Torvalds
2011-12-22 20:23 ` Paolo Bonzini
2011-12-22 20:52 ` Linus Torvalds
2011-12-22 22:08 ` Paolo Bonzini
2011-12-22 22:25 ` Linus Torvalds
2011-12-22 23:48 ` Alasdair G Kergon [this message]
2011-12-23 0:07 ` Linus Torvalds
2011-12-23 6:26 ` Willy Tarreau
2011-12-23 9:22 ` Linus Torvalds
2011-12-23 9:45 ` Willy Tarreau
2011-12-23 14:15 ` Paolo Bonzini
2011-12-23 22:46 ` Linus Torvalds
2012-01-05 13:18 ` Paolo Bonzini
2012-01-05 16:16 ` Linus Torvalds
2012-01-05 16:40 ` Paolo Bonzini
2012-01-05 17:04 ` Linus Torvalds
2012-01-05 17:26 ` Paolo Bonzini
2012-01-05 23:49 ` Linus Torvalds
2011-12-26 1:41 ` Daniel Barkalow
2011-12-23 0:17 ` H. Peter Anvin
2011-12-22 18:02 ` [PATCH 3/3] dm: do not forward ioctls from logical volumes to the underlying device Paolo Bonzini
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