From: Matthew Garrett <mjg59@google.com>
To: Ian Abbott <abbotti@mev.co.uk>
Cc: LSM List <linux-security-module@vger.kernel.org>,
linux-pci@vger.kernel.org
Subject: Re: Should PCI "new_id" support be disabled when kernel is locked down?
Date: Wed, 4 Sep 2019 09:47:30 -0700 [thread overview]
Message-ID: <CACdnJuumhcFw2394J-ymAq1VVAGXpknhdd1T8x565pcU6eAU-w@mail.gmail.com> (raw)
In-Reply-To: <cf90a8aa-536e-f4df-0b2f-60724e4034fb@mev.co.uk>
On Wed, Sep 4, 2019 at 9:12 AM Ian Abbott <abbotti@mev.co.uk> wrote:
>
> Hello,
>
> The "new_id" PCI driver sysfs attribute can be used to make an arbitrary
> PCI driver match an arbitrary PCI vendor/device ID. That could easily
> crash the kernel or at least make it do weird things if used
> inappropriately. Is this scenario in scope for the "lockdown" security
> module?
Crashing the kernel isn't really a concern - the issue is more whether
it's possible to get a driver to perform a sufficient number of writes
to a device that it can in turn cause the device to overwrite the
kernel in a controlled manner. This seems theoretically possible, but
I think I'm inclined to leave it as is unless someone demonstrates
that it's more than theoretical.
prev parent reply other threads:[~2019-09-04 16:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 15:59 Should PCI "new_id" support be disabled when kernel is locked down? Ian Abbott
2019-09-04 16:47 ` Matthew Garrett [this message]
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