[PATCH 4/7] firmware_class: perform new LSM checks

Kees Cook
2014-07-14T21:38:45Z

This attaches LSM hooks to the existing firmware loading interfaces:
filesystem-found firmware and demand-loaded blobs.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/base/firmware_class.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index d276e33880be..7399bab71ced 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -28,6 +28,7 @@
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/reboot.h>
+#include <linux/security.h>

#include <generated/utsrelease.h>

@@ -308,12 +309,17 @@ static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
if (rc != size) {
if (rc > 0)
rc = -EIO;
- vfree(buf);
- return rc;
+ goto fail;
}
+ rc = security_kernel_fw_from_file(file, buf, size);
+ if (rc)
+ goto fail;
fw_buf->data = buf;
fw_buf->size = size;
return 0;
+fail:
+ vfree(buf);
+ return rc;
}

static int fw_get_filesystem_firmware(struct device *device,
@@ -640,6 +646,12 @@ static ssize_t firmware_loading_store(struct device *dev,
break;
case 0:
if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
+ if (security_kernel_fw_from_file(NULL, fw_buf->data,
+ fw_buf->size)) {
+ fw_load_abort(fw_priv);
+ break;
+ }
+
set_bit(FW_STATUS_DONE, &fw_buf->status);
clear_bit(FW_STATUS_LOADING, &fw_buf->status);

--
1.7.9.5