Messages in this thread | | | Date | Mon, 26 Jun 2017 13:39:12 -0600 | From | Alex Williamson <> | Subject | Re: [PATCH v3 7/9] vfio: Use driver_override to avert binding to compromising drivers |
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On Mon, 26 Jun 2017 10:08:55 +0100 Russell King - ARM Linux <linux@armlinux.org.uk> wrote:
> On Tue, Jun 20, 2017 at 09:48:31AM -0600, Alex Williamson wrote: > > If a device is bound to a non-vfio, non-whitelisted driver while a > > group is in use, then the integrity of the group is compromised and > > will result in hitting a BUG_ON. This code tries to avoid this case > > by mangling driver_override to force a no-match for the driver. The > > driver-core will either follow-up with a DRIVER_NOT_BOUND (preferred) > > or BOUND_DRIVER, at which point we can remove the driver_override > > mangling. > > Rather than mangling the driver override string to prevent driver binding, > I wonder if it would make more sense to allow the BUS_NOTIFY_BIND_DRIVER > notifier to fail the device probe? > > The driver override strings are, after all, exposed to userspace, and > it strikes me that this kind of mangling is racy - userspace can read > or change the override string at any time.
Indeed, that looks easier. I sent and RFC, let's see what Greg has to say. Thanks,
Alex
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