On Wed, Oct 31, 2012 at 10:50 AM, Jiri Kosina <jkosina@xxxxxxx> wrote: > On Mon, 29 Oct 2012, Matthew Garrett wrote: > >> > > This is pretty much identical to the first patchset, but with the capability >> > > renamed (CAP_COMPROMISE_KERNEL) and the kexec patch dropped. If anyone wants >> > > to deploy these then they should disable kexec until support for signed >> > > kexec payloads has been merged. >> > >> > Apparently your patchset currently doesn't handle device firmware loading, >> > nor do you seem to mention in in the comments. >> >> Correct. >> >> > I believe signed firmware loading should be put on plate as well, right? >> >> I think that's definitely something that should be covered. I hadn't >> worried about it immediately as any attack would be limited to machines >> with a specific piece of hardware, and the attacker would need to expend >> a significant amount of reverse engineering work on the firmware - and >> we'd probably benefit from them doing that in the long run... > > Now -- how about resuming from S4? > > Reading stored memory image (potentially tampered before reboot) from disk > is basically DMA-ing arbitrary data over the whole RAM. I am currently not > able to imagine a scenario how this could be made "secure" (without > storing private keys to sign the hibernation image on the machine itself > which, well, doesn't sound secure either). I have a patch that disables that. I imagine it will be included in the next submission of the patchset. You can find it here in the meantime: http://jwboyer.fedorapeople.org/pub/0001-hibernate-Disable-in-a-Secure-Boot-environment.patch josh -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
