firmware_class: perform new LSM checks
This attaches LSM hooks to the existing firmware loading interfaces:
filesystem-found firmware and demand-loaded blobs. On errors, loads
are aborted and the failure code is returned to userspace.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index d276e33..63f165c 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 @@
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,
@@ -617,6 +623,7 @@
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware_buf *fw_buf;
+ ssize_t written = count;
int loading = simple_strtol(buf, NULL, 10);
int i;
@@ -640,6 +647,8 @@
break;
case 0:
if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
+ int rc;
+
set_bit(FW_STATUS_DONE, &fw_buf->status);
clear_bit(FW_STATUS_LOADING, &fw_buf->status);
@@ -649,10 +658,23 @@
* see the mapped 'buf->data' once the loading
* is completed.
* */
- if (fw_map_pages_buf(fw_buf))
+ rc = fw_map_pages_buf(fw_buf);
+ if (rc)
dev_err(dev, "%s: map pages failed\n",
__func__);
+ else
+ rc = security_kernel_fw_from_file(NULL,
+ fw_buf->data, fw_buf->size);
+
+ /*
+ * Same logic as fw_load_abort, only the DONE bit
+ * is ignored and we set ABORT only on failure.
+ */
list_del_init(&fw_buf->pending_list);
+ if (rc) {
+ set_bit(FW_STATUS_ABORT, &fw_buf->status);
+ written = rc;
+ }
complete_all(&fw_buf->completion);
break;
}
@@ -666,7 +688,7 @@
}
out:
mutex_unlock(&fw_lock);
- return count;
+ return written;
}
static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);