Messages in this thread Patch in this message | | | Subject | [PATCH 16/24] ACPI: Limit access to custom_method when the kernel is locked down | From | David Howells <> | Date | Wed, 05 Apr 2017 18:12:19 +0100 |
| |
From: Matthew Garrett <matthew.garrett@nebula.com>
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 <matthew.garrett@nebula.com> Signed-off-by: David Howells <dhowells@redhat.com> ---
drivers/acpi/custom_method.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c index c68e72414a67..e4d721c330c0 100644 --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -29,6 +29,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf, struct acpi_table_header table; acpi_status status; + if (kernel_is_locked_down()) + return -EPERM; + if (!(*ppos)) { /* parse the table header to get the table length */ if (count <= sizeof(struct acpi_table_header))
| |