linux-kernel - RE: [PATCH 0/2] efivars: reading variables can generate SMIs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 16 Feb 2018 21:09:30 +0000
From:   "Luck, Tony" <tony.luck@...el.com>
To:     James Bottomley <James.Bottomley@...senPartnership.com>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Joe Konno <joe.konno@...ux.intel.com>,
        "Matthew Garrett" <mjg59@...gle.com>,
        Ingo Molnar <mingo@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Borislav Petkov <bp@...en8.de>
CC:     "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        "Linux Kernel Mailing List" <linux-kernel@...r.kernel.org>,
        Jeremy Kerr <jk@...abs.org>, Andi Kleen <ak@...ux.intel.com>,
        Benjamin Drung <benjamin.drung@...fitbricks.com>,
        Peter Jones <pjones@...hat.com>
Subject: RE: [PATCH 0/2] efivars: reading variables can generate SMIs

> That said, I'm not sure how many non-root users run the toolkit to
> extract their EFI certificates or check on the secure boot status of
> the system, but I suspect it might be non-zero: I can see the tinfoil
> hat people wanting at least to check the secure boot status when they
> log in.

Another fix option might be to rate limit EFI calls for non-root users (on X86
since only we have the SMI problem). That would:

1) Avoid using memory to cache all the variables
2) Catch any other places where non-root users can call EFI

-Tony