From: Matthew Garrett <mjg59@google.com> To: oiaohm@gmail.com Cc: Linus Torvalds <torvalds@linux-foundation.org>, luto@kernel.org, David Howells <dhowells@redhat.com>, 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 Date: Wed, 04 Apr 2018 16:26:43 +0000 [thread overview] Message-ID: <CACdnJuuXgpnkMw8oacgadJQL5nE897cw3-RZBqV7df+19NuiMQ@mail.gmail.com> (raw) In-Reply-To: <CANA3KFXyUH4cEJVTH-yoTwqAnZ+-9h-uboYTzO642Uo78H_wqg@mail.gmail.com> On Tue, Apr 3, 2018 at 11:56 PM Peter Dolding <oiaohm@gmail.com> wrote: > On Wed, Apr 4, 2018 at 11:13 AM, Matthew Garrett <mjg59@google.com> wrote: > > There are four cases: > > > > Verified Boot off, lockdown off: Status quo in distro and mainline kernels > > Verified Boot off, lockdown on: Perception of security improvement that's > > trivially circumvented (and so bad) > > Verified Boot on, lockdown off: Perception of security improvement that's > > trivially circumvented (and so bad), status quo in mainline kernels > > Verified Boot on, lockdown on: Security improvement, status quo in distro > > kernels > > > > Of these four options, only two make sense. The most common implementation > > of Verified Boot on x86 platforms is UEFI Secure Boot, > Stop right there. Verified boot does not have to be UEFI secureboot. > You could be using a uboot verified boot or > https://www.coreboot.org/git-docs/Intel/vboot.html google vboot. > Neither of these provide flags to kernel to say they have been > performed. They can be modified to set the appropriate bit in the bootparams - the reason we can't do that in the UEFI case is that Linux can be built as a UEFI binary that the firmware execute directly, and so the firmware has no way to set that flag. > Now Verified Boot on, lockdown off. Insanely this can be required in > diagnostic on some embedded platform because EFI secureboot does not > have a off switch. These are platforms where they don't boot if > they don't have a PK and KEK set installed. Yes some of these is jtag > the PK and KEK set in. > The fact that this Verified Boot on, lockdown off causes trouble > points to a clear problem. User owns the hardware they should have > the right to defeat secureboot if they wish to. Which is why Shim allows you to disable validation if you prove physical user presence.
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From: mjg59@google.com (Matthew Garrett) To: linux-security-module@vger.kernel.org Subject: [GIT PULL] Kernel lockdown for secure boot Date: Wed, 04 Apr 2018 16:26:43 +0000 [thread overview] Message-ID: <CACdnJuuXgpnkMw8oacgadJQL5nE897cw3-RZBqV7df+19NuiMQ@mail.gmail.com> (raw) In-Reply-To: <CANA3KFXyUH4cEJVTH-yoTwqAnZ+-9h-uboYTzO642Uo78H_wqg@mail.gmail.com> On Tue, Apr 3, 2018 at 11:56 PM Peter Dolding <oiaohm@gmail.com> wrote: > On Wed, Apr 4, 2018 at 11:13 AM, Matthew Garrett <mjg59@google.com> wrote: > > There are four cases: > > > > Verified Boot off, lockdown off: Status quo in distro and mainline kernels > > Verified Boot off, lockdown on: Perception of security improvement that's > > trivially circumvented (and so bad) > > Verified Boot on, lockdown off: Perception of security improvement that's > > trivially circumvented (and so bad), status quo in mainline kernels > > Verified Boot on, lockdown on: Security improvement, status quo in distro > > kernels > > > > Of these four options, only two make sense. The most common implementation > > of Verified Boot on x86 platforms is UEFI Secure Boot, > Stop right there. Verified boot does not have to be UEFI secureboot. > You could be using a uboot verified boot or > https://www.coreboot.org/git-docs/Intel/vboot.html google vboot. > Neither of these provide flags to kernel to say they have been > performed. They can be modified to set the appropriate bit in the bootparams - the reason we can't do that in the UEFI case is that Linux can be built as a UEFI binary that the firmware execute directly, and so the firmware has no way to set that flag. > Now Verified Boot on, lockdown off. Insanely this can be required in > diagnostic on some embedded platform because EFI secureboot does not > have a off switch. These are platforms where they don't boot if > they don't have a PK and KEK set installed. Yes some of these is jtag > the PK and KEK set in. > The fact that this Verified Boot on, lockdown off causes trouble > points to a clear problem. User owns the hardware they should have > the right to defeat secureboot if they wish to. Which is why Shim allows you to disable validation if you prove physical user presence. -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2018-04-04 16:26 UTC|newest] Thread overview: 252+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-03-30 23:29 [GIT PULL] Kernel lockdown for secure boot David Howells 2018-03-30 23:29 ` David Howells 2018-03-31 0:46 ` James Morris 2018-03-31 0:46 ` James Morris 2018-04-03 0:37 ` Andy Lutomirski 2018-04-03 0:37 ` Andy Lutomirski 2018-04-03 0:59 ` Kees Cook 2018-04-03 0:59 ` Kees Cook 2018-04-03 1:47 ` Andy Lutomirski 2018-04-03 1:47 ` Andy Lutomirski 2018-04-03 7:06 ` David Howells 2018-04-03 7:06 ` David Howells 2018-04-03 15:11 ` Andy Lutomirski 2018-04-03 15:11 ` Andy Lutomirski 2018-04-03 15:41 ` Alexei Starovoitov 2018-04-03 15:41 ` Alexei Starovoitov 2018-04-03 16:26 ` Andy Lutomirski 2018-04-03 16:26 ` Andy Lutomirski 2018-04-03 16:29 ` Matthew Garrett 2018-04-03 16:29 ` Matthew Garrett 2018-04-03 16:45 ` Andy Lutomirski 2018-04-03 16:45 ` Andy Lutomirski 2018-04-03 18:45 ` Kees Cook 2018-04-03 18:45 ` Kees Cook 2018-04-03 19:01 ` Andy Lutomirski 2018-04-03 19:01 ` Andy Lutomirski 2018-04-03 19:07 ` Kees Cook 2018-04-03 19:07 ` Kees Cook 2018-04-03 19:29 ` Matthew Garrett 2018-04-03 19:29 ` Matthew Garrett 2018-04-03 21:51 ` Andy Lutomirski 2018-04-03 21:51 ` Andy Lutomirski 2018-04-04 18:42 ` Peter Jones 2018-04-04 18:42 ` Peter Jones 2018-04-04 20:01 ` Thomas Gleixner 2018-04-04 20:01 ` Thomas Gleixner 2018-04-04 20:18 ` Matthew Garrett 2018-04-04 20:18 ` Matthew Garrett 2018-04-05 18:47 ` Andy Lutomirski 2018-04-05 18:47 ` Andy Lutomirski 2018-04-06 4:42 ` Peter Dolding 2018-04-06 4:42 ` Peter Dolding 2018-04-03 17:16 ` David Howells 2018-04-03 17:16 ` David Howells 2018-04-03 19:01 ` Andy Lutomirski 2018-04-03 19:01 ` Andy Lutomirski 2018-04-03 19:49 ` David Howells 2018-04-03 19:49 ` David Howells 2018-04-03 21:58 ` Andy Lutomirski 2018-04-03 21:58 ` Andy Lutomirski 2018-04-03 22:32 ` David Howells 2018-04-03 22:32 ` David Howells 2018-04-03 22:39 ` Andy Lutomirski 2018-04-03 22:39 ` Andy Lutomirski 2018-04-03 22:46 ` Linus Torvalds 2018-04-03 22:46 ` Linus Torvalds 2018-04-03 22:51 ` Matthew Garrett 2018-04-03 22:51 ` Matthew Garrett 2018-04-03 22:53 ` Andy Lutomirski 2018-04-03 22:53 ` Andy Lutomirski 2018-04-03 23:08 ` Justin Forbes 2018-04-03 23:09 ` Matthew Garrett 2018-04-03 23:09 ` Matthew Garrett 2018-04-03 23:08 ` Linus Torvalds 2018-04-03 23:08 ` Linus Torvalds 2018-04-03 23:10 ` Linus Torvalds 2018-04-03 23:10 ` Linus Torvalds 2018-04-03 23:17 ` Matthew Garrett 2018-04-03 23:17 ` Matthew Garrett 2018-04-03 23:26 ` Linus Torvalds 2018-04-03 23:26 ` Linus Torvalds 2018-04-03 23:39 ` Linus Torvalds 2018-04-03 23:39 ` Linus Torvalds 2018-04-03 23:47 ` Matthew Garrett 2018-04-03 23:47 ` Matthew Garrett 2018-04-04 0:02 ` Linus Torvalds 2018-04-04 0:02 ` Linus Torvalds 2018-04-04 0:04 ` Matthew Garrett 2018-04-04 0:04 ` Matthew Garrett 2018-04-04 0:08 ` Linus Torvalds 2018-04-04 0:08 ` Linus Torvalds 2018-04-04 0:12 ` Matthew Garrett 2018-04-04 0:12 ` Matthew Garrett 2018-04-05 14:58 ` Alan Cox 2018-04-05 14:58 ` Alan Cox 2018-04-04 0:22 ` David Howells 2018-04-04 0:22 ` David Howells 2018-04-04 0:22 ` David Howells 2018-04-05 17:59 ` Alan Cox 2018-04-05 17:59 ` Alan Cox 2018-04-05 18:03 ` Matthew Garrett 2018-04-05 18:03 ` Matthew Garrett 2018-04-03 23:45 ` Matthew Garrett 2018-04-03 23:45 ` Matthew Garrett 2018-04-03 23:55 ` Linus Torvalds 2018-04-03 23:55 ` Linus Torvalds 2018-04-03 23:59 ` Matthew Garrett 2018-04-03 23:59 ` Matthew Garrett 2018-04-04 0:06 ` Linus Torvalds 2018-04-04 0:06 ` Linus Torvalds 2018-04-04 0:10 ` Matthew Garrett 2018-04-04 0:10 ` Matthew Garrett 2018-04-04 0:15 ` Linus Torvalds 2018-04-04 0:15 ` Linus Torvalds 2018-04-04 0:16 ` Matthew Garrett 2018-04-04 0:16 ` Matthew Garrett 2018-04-04 0:18 ` Andy Lutomirski 2018-04-04 0:18 ` Andy Lutomirski 2018-04-04 0:19 ` Matthew Garrett 2018-04-04 0:19 ` Matthew Garrett 2018-04-04 9:04 ` Greg Kroah-Hartman 2018-04-04 9:04 ` Greg Kroah-Hartman 2018-04-04 0:25 ` Linus Torvalds 2018-04-04 0:25 ` Linus Torvalds 2018-04-04 0:33 ` Linus Torvalds 2018-04-04 0:33 ` Linus Torvalds 2018-04-04 0:46 ` Matthew Garrett 2018-04-04 0:46 ` Matthew Garrett 2018-04-04 0:56 ` Linus Torvalds 2018-04-04 0:56 ` Linus Torvalds 2018-04-04 1:13 ` Matthew Garrett 2018-04-04 1:13 ` Matthew Garrett 2018-04-04 1:43 ` Linus Torvalds 2018-04-04 1:43 ` Linus Torvalds 2018-04-04 4:30 ` Matthew Garrett 2018-04-04 4:30 ` Matthew Garrett 2018-04-04 12:57 ` Theodore Y. Ts'o 2018-04-04 12:57 ` Theodore Y. Ts'o 2018-04-04 13:02 ` Greg Kroah-Hartman 2018-04-04 13:02 ` Greg Kroah-Hartman 2018-04-04 13:34 ` Theodore Y. Ts'o 2018-04-04 13:34 ` Theodore Y. Ts'o 2018-04-04 13:57 ` Greg Kroah-Hartman 2018-04-04 13:57 ` Greg Kroah-Hartman 2018-04-04 13:29 ` Mike Galbraith 2018-04-04 13:29 ` Mike Galbraith 2018-04-04 16:20 ` Matthew Garrett 2018-04-04 16:20 ` Matthew Garrett 2018-04-08 22:00 ` Pavel Machek 2018-04-04 13:33 ` David Howells 2018-04-04 13:33 ` David Howells 2018-04-04 13:52 ` Theodore Y. Ts'o 2018-04-04 13:52 ` Theodore Y. Ts'o 2018-04-04 16:22 ` Matthew Garrett 2018-04-04 16:22 ` Matthew Garrett 2018-04-04 16:39 ` Andy Lutomirski 2018-04-04 16:39 ` Andy Lutomirski 2018-04-04 16:42 ` Matthew Garrett 2018-04-04 16:42 ` Matthew Garrett 2018-04-04 16:46 ` Justin Forbes 2018-04-04 16:46 ` Justin Forbes 2018-04-05 0:05 ` Peter Dolding 2018-04-05 0:05 ` Peter Dolding 2018-04-05 0:20 ` Matthew Garrett 2018-04-05 0:20 ` Matthew Garrett 2018-04-04 13:57 ` David Howells 2018-04-04 13:57 ` David Howells 2018-04-04 16:09 ` Linus Torvalds 2018-04-04 16:09 ` Linus Torvalds 2018-04-04 16:17 ` Matthew Garrett 2018-04-04 16:17 ` Matthew Garrett 2018-04-04 6:56 ` Peter Dolding 2018-04-04 6:56 ` Peter Dolding 2018-04-04 16:26 ` Matthew Garrett [this message] 2018-04-04 16:26 ` Matthew Garrett 2018-04-05 1:28 ` Peter Dolding 2018-04-05 1:28 ` Peter Dolding 2018-04-04 1:30 ` Justin Forbes 2018-04-04 1:58 ` Linus Torvalds 2018-04-04 1:58 ` Linus Torvalds 2018-04-04 1:36 ` Justin Forbes 2018-04-04 1:36 ` Justin Forbes 2018-04-04 0:17 ` Jann Horn 2018-04-04 0:17 ` Jann Horn 2018-04-04 0:23 ` Andy Lutomirski 2018-04-04 0:23 ` Andy Lutomirski 2018-04-04 8:05 ` David Howells 2018-04-04 8:05 ` David Howells 2018-04-04 8:05 ` David Howells 2018-04-04 14:35 ` Andy Lutomirski 2018-04-04 14:35 ` Andy Lutomirski 2018-04-04 14:44 ` David Howells 2018-04-04 14:44 ` David Howells 2018-04-04 14:44 ` David Howells 2018-04-04 15:43 ` Eric W. Biederman 2018-04-04 15:43 ` Eric W. Biederman 2018-04-03 23:56 ` David Howells 2018-04-03 23:56 ` David Howells 2018-04-03 23:56 ` David Howells 2018-04-03 23:58 ` Linus Torvalds 2018-04-03 23:58 ` Linus Torvalds 2018-04-03 23:39 ` David Howells 2018-04-03 23:39 ` David Howells 2018-04-03 23:48 ` Andy Lutomirski 2018-04-03 23:48 ` Andy Lutomirski 2018-04-08 8:23 ` Pavel Machek 2018-04-03 23:12 ` David Howells 2018-04-03 23:12 ` David Howells 2018-04-03 23:27 ` Linus Torvalds 2018-04-03 23:27 ` Linus Torvalds 2018-04-03 23:42 ` Andy Lutomirski 2018-04-03 23:42 ` Andy Lutomirski 2018-04-03 20:53 ` Linus Torvalds 2018-04-03 20:53 ` Linus Torvalds 2018-04-03 20:54 ` Matthew Garrett 2018-04-03 20:54 ` Matthew Garrett 2018-04-03 21:01 ` Linus Torvalds 2018-04-03 21:01 ` Linus Torvalds 2018-04-03 21:08 ` Matthew Garrett 2018-04-03 21:08 ` Matthew Garrett 2018-04-03 21:21 ` Al Viro 2018-04-03 21:21 ` Al Viro 2018-04-03 21:37 ` Matthew Garrett 2018-04-03 21:37 ` Matthew Garrett 2018-04-03 21:26 ` Linus Torvalds 2018-04-03 21:26 ` Linus Torvalds 2018-04-03 21:32 ` Matthew Garrett 2018-04-03 21:32 ` Matthew Garrett 2018-04-08 8:10 ` Pavel Machek 2018-03-31 10:20 ` David Howells 2018-03-31 10:20 ` David Howells 2018-04-03 13:25 ` Ard Biesheuvel 2018-04-03 13:25 ` Ard Biesheuvel 2018-04-03 21:48 ` James Morris 2018-04-03 21:48 ` James Morris 2018-04-05 17:53 ` Alan Cox 2018-04-05 17:53 ` Alan Cox 2018-11-21 12:05 ` [PATCH next-lockdown 0/1] debugfs EPERM fix for 'Kernel lockdown for secure boot' patch series Vasily Gorbik 2018-11-21 12:05 ` [PATCH next-lockdown 1/1] debugfs: avoid EPERM when no open file operation defined Vasily Gorbik -- strict thread matches above, loose matches on Subject: below -- 2018-04-04 2:34 [GIT PULL] Kernel lockdown for secure boot Alexei Starovoitov 2018-04-04 2:34 ` Alexei Starovoitov 2018-04-04 4:31 ` Matthew Garrett 2018-04-04 4:31 ` Matthew Garrett 2018-04-08 7:44 ` joeyli 2018-04-08 7:44 ` joeyli 2018-04-08 8:07 ` joeyli 2018-04-08 8:07 ` joeyli 2018-04-09 3:40 ` Alexei Starovoitov 2018-04-09 3:40 ` Alexei Starovoitov 2018-04-09 8:14 ` Daniel Borkmann 2018-04-09 8:14 ` Daniel Borkmann 2018-04-09 13:55 ` joeyli 2018-04-09 13:55 ` joeyli 2017-10-26 16:37 David Howells 2017-10-26 16:37 ` David Howells 2017-10-26 16:37 ` David Howells 2017-10-26 18:22 ` Mimi Zohar 2017-10-26 18:22 ` Mimi Zohar 2017-10-26 18:22 ` Mimi Zohar 2017-10-26 19:20 ` James Morris 2017-10-26 19:20 ` James Morris 2017-10-26 19:20 ` James Morris
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