On Fri, Feb 16, 2018 at 10:03 PM, Matthew Garrett <mjg59@xxxxxxxxxx> wrote: > On Fri, Feb 16, 2018 at 2:02 PM Luck, Tony <tony.luck@xxxxxxxxx> wrote: > >> > If the default is 600 then it makes sense to allow a privileged service > to >> > selectively make certain variables world readable at runtime. > >> As soon as you make one variable world readable you are vulnerable to >> a local user launching a DoS attack by reading that variable over and over >> generating a flood of SMIs. > > I'm not terribly worried about untrusted users on my laptop, but I would > prefer to run as little code as root as possible. I think that, for the most part, systemwide configuration should not be accessible to non-root. Unprivileged users, in general, have no legitimate reason to know that my default boot is Boot0000* Fedora HD(1,GPT,ee...,0x800,0x64000)/File(\EFI\fedora\shim.efi). Even more so if I'm network booting. Alternatively, we could call this a distro issue. Distros could easily change the permissions on /sys/firmware/efi/efivars to disallow unprivileged access. -- 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
