From: David Howells <dhowells@redhat.com>
To: Jiri Bohac <jbohac@suse.cz>
Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org,
gnomes@lxorguk.ukuu.org.uk, linux-efi@vger.kernel.org,
linux-kernel@vger.kernel.org, jforbes@redhat.com,
Chun-Yi Lee <joeyli.kernel@gmail.com>
Subject: Re: [PATCH 08/30] kexec_file: Restrict at runtime if the kernel is locked down
Date: Thu, 11 Jan 2018 12:47:57 +0000 [thread overview]
Message-ID: <13005.1515674877@warthog.procyon.org.uk> (raw)
In-Reply-To: <12880.1515674600@warthog.procyon.org.uk>
David Howells <dhowells@redhat.com> wrote:
> > I don't like the idea that the lockdown (which is a runtime
> > thing) requires a compile time option (KEXEC_VERIFY_SIG) that
> > forces the verification even when the kernel is then not locked
> > down at runtime.
>
> It doesn't. The EPERM only triggers if:
>
> (1) File signatures aren't mandatory (ie. CONFIG_KEXEC_VERIFY_SIG) is not
> set, and
>
> (2) you're not using IMA appraisal to validate the file contents, and
>
> (3) lockdown mode is enabled.
>
> If file signatures are mandatory or IMA appraisal is in use, then the lockdown
> state doesn't need to be checked.
Having said that, I do see your point, I think. We should still let through
validly signed images, even if signatures aren't mandatory in lockdown mode.
David
next prev parent reply other threads:[~2018-01-11 12:48 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
2018-02-22 13:07 ` David Howells
2018-02-22 18:44 ` Jiri Bohac
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
2018-01-16 16:31 ` 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 12:02 ` [PATCH 08b/30] kexec_file: Restrict at runtime if the kernel is locked down Jiri Bohac
2018-01-11 12:43 ` [PATCH 08/30] " David Howells
2018-01-11 12:47 ` David Howells [this message]
2018-01-11 15:44 ` Jiri Bohac
2018-01-17 16:16 ` David Howells
2018-02-22 14:20 ` David Howells
2018-02-22 14:21 ` David Howells
2018-02-22 19:14 ` Jiri Bohac
2018-02-22 19:08 ` Jiri Bohac
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
2018-03-03 1:18 ` [PATCH 00/30] security, efi: Add kernel lockdown Andrew Morton
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