From: Kees Cook <keescook@chromium.org>
To: Matthew Garrett <matthewgarrett@google.com>
Cc: jmorris@namei.org, linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
Josh Boyer <jwboyer@redhat.com>,
David Howells <dhowells@redhat.com>,
Matthew Garrett <mjg59@google.com>,
Dave Young <dyoung@redhat.com>,
linux-acpi@vger.kernel.org
Subject: Re: [PATCH V34 15/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
Date: Sat, 22 Jun 2019 16:59:44 -0700 [thread overview]
Message-ID: <201906221659.A04260B5@keescook> (raw)
In-Reply-To: <20190622000358.19895-16-matthewgarrett@google.com>
On Fri, Jun 21, 2019 at 05:03:44PM -0700, Matthew Garrett wrote:
> From: Josh Boyer <jwboyer@redhat.com>
>
> This option allows userspace to pass the RSDP address to the kernel, which
> makes it possible for a user to modify the workings of hardware . Reject
> the option when the kernel is locked down.
>
> Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> Signed-off-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Matthew Garrett <mjg59@google.com>
> cc: Dave Young <dyoung@redhat.com>
> cc: linux-acpi@vger.kernel.org
> ---
> drivers/acpi/osl.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index f29e427d0d1d..60cda8a0f36b 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -40,6 +40,7 @@
> #include <linux/list.h>
> #include <linux/jiffies.h>
> #include <linux/semaphore.h>
> +#include <linux/security.h>
>
> #include <asm/io.h>
> #include <linux/uaccess.h>
> @@ -194,7 +195,7 @@ acpi_physical_address __init acpi_os_get_root_pointer(void)
> acpi_physical_address pa;
>
> #ifdef CONFIG_KEXEC
> - if (acpi_rsdp)
> + if (acpi_rsdp && !security_locked_down(LOCKDOWN_ACPI_TABLES))
> return acpi_rsdp;
> #endif
> pa = acpi_arch_get_root_pointer();
> --
> 2.22.0.410.gd8fdbe21b5-goog
>
--
Kees Cook
next prev parent reply other threads:[~2019-06-22 23:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190622000358.19895-1-matthewgarrett@google.com>
2019-06-22 0:03 ` [PATCH V34 14/29] ACPI: Limit access to custom_method when the kernel is locked down Matthew Garrett
2019-06-22 23:59 ` Kees Cook
2019-06-22 0:03 ` [PATCH V34 15/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-06-22 23:59 ` Kees Cook [this message]
2019-06-22 0:03 ` [PATCH V34 16/29] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-06-23 0:00 ` Kees Cook
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