diff options
| author | Matthew Garrett <mjg59@srcf.ucam.org> | 2019-08-19 17:17:50 -0700 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2019-08-19 21:54:16 -0700 |
| commit | f474e1486b78ac15322f8a1cda48a32a1deff9d3 (patch) | |
| tree | fe775561f6ce6e2a47ec9b837d398e5ab987efdd /drivers | |
| parent | 95f5e95f41dff31b2a4566c5a8975c08a49ae4e3 (diff) | |
ACPI: Limit access to custom_method when the kernel is locked down
custom_method effectively allows arbitrary access to system memory, making
it possible for an attacker to circumvent restrictions on module loading.
Disable it if the kernel is locked down.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
cc: linux-acpi@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/custom_method.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c index b2ef4c2ec955..7031307becd7 100644 --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -9,6 +9,7 @@ #include <linux/uaccess.h> #include <linux/debugfs.h> #include <linux/acpi.h> +#include <linux/security.h> #include "internal.h" @@ -29,6 +30,11 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf, struct acpi_table_header table; acpi_status status; + int ret; + + ret = security_locked_down(LOCKDOWN_ACPI_TABLES); + if (ret) + return ret; if (!(*ppos)) { /* parse the table header to get the table length */ |