From: Matthew Garrett <matthew.garrett@nebula.com>
Date: Mon, 9 Sep 2013 22:49:41 +0000 (-0700)
Subject: acpi: Ignore acpi_rsdp kernel parameter when securelevel is set
X-Git-Tag: v4.1.12-92~310^2~8
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ad0eb71d4366e8375d91ab39c40c30e04eba9171;p=users%2Fjedix%2Flinux-maple.git

acpi: Ignore acpi_rsdp kernel parameter when securelevel is set

Orabug: 21539498

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 execute arbitrary code in the kernel.
Disable this when securelevel is set.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
---

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 7ccba395c9ddb..5a2e173cf3158 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -44,6 +44,7 @@
 #include <linux/list.h>
 #include <linux/jiffies.h>
 #include <linux/semaphore.h>
+#include <linux/security.h>
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
@@ -252,7 +253,7 @@ early_param("acpi_rsdp", setup_acpi_rsdp);
 acpi_physical_address __init acpi_os_get_root_pointer(void)
 {
 #ifdef CONFIG_KEXEC
-	if (acpi_rsdp)
+	if (acpi_rsdp && (get_securelevel() <= 0))
 		return acpi_rsdp;
 #endif