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From:   David Howells <dhowells@redhat.com>
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To:     "Theodore Y. Ts'o" <tytso@mit.edu>
Cc:     dhowells@redhat.com, Matthew Garrett <mjg59@google.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        luto@kernel.org, Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        jmorris@namei.org, Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        jforbes@redhat.com, linux-man@vger.kernel.org, jlee@suse.com,
        LSM List <linux-security-module@vger.kernel.org>,
        linux-api@vger.kernel.org, Kees Cook <keescook@chromium.org>,
        linux-efi <linux-efi@vger.kernel.org>
Subject: Re: [GIT PULL] Kernel lockdown for secure boot
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Date:   Wed, 04 Apr 2018 14:33:37 +0100
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Theodore Y. Ts'o <tytso@mit.edu> wrote:

> Whoa.  Why doesn't lockdown prevent kexec?  Put another away, why
> isn't this a problem for people who are fearful that Linux could be
> used as part of a Windows boot virus in a Secure UEFI context?

Lockdown mode restricts kexec to booting an authorised image (where the
authorisation may be by signature or by IMA).

David