Re: [PATCH 2/2] pci: allow sysfs file owner to read devicedependent config space

From: Greg KH
Date: Fri May 14 2010 - 15:18:04 EST


On Wed, May 12, 2010 at 06:29:57PM -0700, Chris Wright wrote:
> The PCI config space bin_attr read handler has a hardcoded CAP_SYS_ADMIN
> check to verify privileges before allowing a user to read device
> dependent config space. This is meant to protect from an unprivileged
> user potentially locking up the box.
>
> When assigning a PCI device directly to a guest with libvirt and KVM,
> the sysfs config space file is chown'd to the unprivileged user that
> the KVM guest will run as. The guest needs to have full access to the
> device's config space since it's responsible for driving the device.
> However, despite being the owner of the sysfs file, the CAP_SYS_ADMIN
> check will not allow read access beyond the config header.
>
> With this patch the sysfs file owner is also considered privileged enough
> to read all of the config space.
>
> Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
> ---
> drivers/pci/pci-sysfs.c | 4 +++-

Jesse, any objection to this going through my tree as it will depend on
the sysfs change?

thanks,

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/