From: akpm@linux-foundation.org (Andrew Morton)
To: linux-security-module@vger.kernel.org
Subject: [PATCH 00/30] security, efi: Add kernel lockdown
Date: Fri, 2 Mar 2018 17:18:01 -0800 [thread overview]
Message-ID: <20180302171801.6ed00ef19e0b970d90094556@linux-foundation.org> (raw)
In-Reply-To: <151024863544.28329.2436580122759221600.stgit@warthog.procyon.org.uk>
On Thu, 9 Nov 2017 17:30:36 +0000 David Howells <dhowells@redhat.com> wrote:
> Here's a set of patches to institute a "locked-down mode" in the kernel and
> to trigger that mode if the kernel is booted in secure-boot mode or through
> the command line.
>
> Enabling CONFIG_LOCK_DOWN_KERNEL makes lockdown mode available.
>
> Enabling CONFIG_ALLOW_LOCKDOWN_LIFT_BY_SYSRQ will allow a SysRq combination
> to lift the lockdown. On x86 this is SysRq+x. The keys must be pressed on
> an attached keyboard.
>
> Enabling CONFIG_LOCK_DOWN_IN_EFI_SECURE_BOOT will cause EFI secure boot to
> trigger kernel lockdown.
>
> Inside the kernel, kernel_is_locked_down() is used to check if the kernel
> is in lockdown mode.
>
> Note that the secure boot mode entry doesn't work if the kernel is booted
> from older versions of i386/x86_64 Grub as there's a bug in Grub whereby it
> doesn't initialise the boot_params correctly. The incorrect initialisation
> causes sanitize_boot_params() to be triggered, thereby zapping the secure
> boot flag determined by the EFI boot wrapper.
>
> A manual page, kernel_lockdown.7, is proposed, to which people will be
> directed by messages in dmesg. This lists the features that are restricted
> amongst other things. [Note: I need to update this to mention IMA, so I'll
> reply with that later].
I saw all this pop up in linux-next and got curious.
This changelog didn't uncurious me at all. The
LOCK_DOWN_IN_EFI_SECURE_BOOT Kconfig help is unilluminating. A bit of
googling led me to kernel_lockdown.7 (https://lwn.net/Articles/735564/)
which kinda helped.
But still. This is a big, straggly feature and presumably is still
missing things and presumably will require ongoing maintenance as we
add new kernel capabilities. What do we get in return for all of this?
What are the usecases for this feature and why would anyone want one?
What's the value to our users?
Thanks.
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prev parent reply other threads:[~2018-03-03 1:18 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-09 17:30 [PATCH 00/30] security, efi: Add kernel lockdown David Howells
2017-11-09 17:30 ` [PATCH 01/30] Add the ability to lock down access to the running kernel image David Howells
2017-11-09 17:30 ` [PATCH 02/30] Add a SysRq option to lift kernel lockdown David Howells
2017-11-09 17:31 ` [PATCH 03/30] ima: require secure_boot rules in lockdown mode David Howells
2017-11-09 17:31 ` [PATCH 04/30] Enforce module signatures if the kernel is locked down David Howells
2017-11-09 17:31 ` [PATCH 05/30] Restrict /dev/{mem, kmem, port} when " David Howells
2017-11-09 17:31 ` [PATCH 06/30] kexec: Disable at runtime if " David Howells
2017-11-09 17:31 ` [PATCH 07/30] Copy secure_boot flag in boot params across kexec reboot David Howells
2017-11-09 17:31 ` [PATCH 08/30] kexec_file: Restrict at runtime if the kernel is locked down David Howells
2018-01-11 11:59 ` Jiri Bohac
2018-01-11 12:01 ` [PATCH 08a/30] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Jiri Bohac
2018-01-11 12:02 ` [PATCH 08b/30] kexec_file: Restrict at runtime if the kernel is locked down Jiri Bohac
2018-01-16 16:31 ` [PATCH 08a/30] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE David Howells
2018-01-16 19:39 ` Jiri Bohac
2018-01-17 16:34 ` David Howells
2018-01-19 12:54 ` Jiri Bohac
2018-02-21 16:20 ` David Howells
2018-01-11 12:43 ` [PATCH 08/30] kexec_file: Restrict at runtime if the kernel is locked down David Howells
2018-01-11 12:47 ` David Howells
2018-01-11 15:44 ` Jiri Bohac
2018-01-17 16:16 ` David Howells
2017-11-09 17:31 ` [PATCH 09/30] hibernate: Disable when " David Howells
2017-11-09 17:31 ` [PATCH 10/30] uswsusp: " David Howells
2017-11-09 17:32 ` [PATCH 11/30] PCI: Lock down BAR access " David Howells
2017-11-09 17:32 ` [PATCH 12/30] x86: Lock down IO port " David Howells
2017-11-09 17:32 ` [PATCH 13/30] x86/msr: Restrict MSR " David Howells
2017-11-09 17:32 ` [PATCH 14/30] asus-wmi: Restrict debugfs interface " David Howells
2017-11-09 17:32 ` [PATCH 15/30] ACPI: Limit access to custom_method " David Howells
2017-11-09 17:32 ` [PATCH 16/30] acpi: Ignore acpi_rsdp kernel param when the kernel has been " David Howells
2017-11-09 17:32 ` [PATCH 17/30] acpi: Disable ACPI table override if the kernel is " David Howells
2017-11-09 17:32 ` [PATCH 18/30] acpi: Disable APEI error injection " David Howells
2019-11-07 8:21 ` Joey Lee
2022-05-28 0:11 ` joeyli
2017-11-09 17:33 ` [PATCH 19/30] scsi: Lock down the eata driver David Howells
2017-11-09 17:33 ` [PATCH 20/30] Prohibit PCMCIA CIS storage when the kernel is locked down David Howells
2017-11-09 17:33 ` [PATCH 21/30] Lock down TIOCSSERIAL David Howells
2017-11-09 17:33 ` [PATCH 22/30] Lock down module params that specify hardware parameters (eg. ioport) David Howells
2017-11-09 17:33 ` [PATCH 23/30] x86/mmiotrace: Lock down the testmmiotrace module David Howells
2017-11-09 17:33 ` [PATCH 24/30] debugfs: Disallow use of debugfs files when the kernel is locked down David Howells
2017-11-09 17:33 ` [PATCH 25/30] Lock down /proc/kcore David Howells
2017-11-09 17:33 ` [PATCH 26/30] Lock down ftrace David Howells
2017-11-10 9:23 ` Jiri Kosina
2017-11-10 10:07 ` David Howells
2017-11-10 10:15 ` Jiri Kosina
2017-11-10 10:21 ` David Howells
2017-11-10 10:23 ` Jiri Kosina
2017-11-10 11:06 ` David Howells
2017-11-09 17:34 ` [PATCH 27/30] Lock down kprobes David Howells
2017-11-09 17:34 ` [PATCH 28/30] bpf: Restrict kernel image access functions when the kernel is locked down David Howells
2017-11-09 17:34 ` [PATCH 29/30] efi: Add an EFI_SECURE_BOOT flag to indicate secure boot mode David Howells
2017-11-09 17:34 ` [PATCH 30/30] efi: Lock down the kernel if booted in " David Howells
2018-02-22 13:07 ` [PATCH 04/30] Enforce module signatures if the kernel is locked down David Howells
2018-02-22 18:44 ` Jiri Bohac
2018-02-22 14:20 ` [PATCH 08/30] kexec_file: Restrict at runtime " David Howells
2018-02-22 19:08 ` Jiri Bohac
2018-02-22 14:21 ` David Howells
2018-02-22 19:14 ` Jiri Bohac
2018-03-03 1:18 ` Andrew Morton [this message]
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