[PATCH 04/10] ACPI: Limit access to custom_method
From: Matthew Garrett <hidden>
Date: 2013-08-19 16:17:59
Also in:
lkml
Subsystem:
acpi, the rest · Maintainers:
"Rafael J. Wysocki", Linus Torvalds
custom_method effectively allows arbitrary access to system memory, making it possible for an attacker to circumvent restrictions on module loading. Disable it if any such restrictions have been enabled. Signed-off-by: Matthew Garrett <matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org> --- drivers/acpi/custom_method.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
index 12b62f2..55a013f 100644
--- a/drivers/acpi/custom_method.c
+++ b/drivers/acpi/custom_method.c@@ -7,6 +7,7 @@ #include <linux/kernel.h> #include <linux/uaccess.h> #include <linux/debugfs.h> +#include <linux/module.h> #include <acpi/acpi_drivers.h> #include "internal.h"
@@ -29,6 +30,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf, struct acpi_table_header table; acpi_status status; + if (secure_modules()) + return -EPERM; + if (!(*ppos)) { /* parse the table header to get the table length */ if (count <= sizeof(struct acpi_table_header))
--
1.8.3.1