fit: Don't allow verification of images with @ nodes

When searching for a node called 'fred', any unit address appended to the
name is ignored by libfdt, meaning that 'fred' can match 'fred@1'. This
means that we cannot be sure that the node originally intended is the one
that is used.

Disallow use of nodes with unit addresses.

Update the forge test also, since it uses @ addresses.

CVE-2021-27138

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Bruce Monroe <bruce.monroe@intel.com>
Reported-by: Arie Haenel <arie.haenel@intel.com>
Reported-by: Julien Lenoir <julien.lenoir@intel.com>
diff --git a/test/py/tests/test_fit.py b/test/py/tests/test_fit.py
index 84b3f95..6d5b43c 100755
--- a/test/py/tests/test_fit.py
+++ b/test/py/tests/test_fit.py
@@ -17,7 +17,7 @@
         #address-cells = <1>;
 
         images {
-                kernel@1 {
+                kernel-1 {
                         data = /incbin/("%(kernel)s");
                         type = "kernel";
                         arch = "sandbox";
@@ -26,7 +26,7 @@
                         load = <0x40000>;
                         entry = <0x8>;
                 };
-                kernel@2 {
+                kernel-2 {
                         data = /incbin/("%(loadables1)s");
                         type = "kernel";
                         arch = "sandbox";
@@ -35,19 +35,19 @@
                         %(loadables1_load)s
                         entry = <0x0>;
                 };
-                fdt@1 {
+                fdt-1 {
                         description = "snow";
                         data = /incbin/("%(fdt)s");
                         type = "flat_dt";
                         arch = "sandbox";
                         %(fdt_load)s
                         compression = "%(compression)s";
-                        signature@1 {
+                        signature-1 {
                                 algo = "sha1,rsa2048";
                                 key-name-hint = "dev";
                         };
                 };
-                ramdisk@1 {
+                ramdisk-1 {
                         description = "snow";
                         data = /incbin/("%(ramdisk)s");
                         type = "ramdisk";
@@ -56,7 +56,7 @@
                         %(ramdisk_load)s
                         compression = "%(compression)s";
                 };
-                ramdisk@2 {
+                ramdisk-2 {
                         description = "snow";
                         data = /incbin/("%(loadables2)s");
                         type = "ramdisk";
@@ -67,10 +67,10 @@
                 };
         };
         configurations {
-                default = "conf@1";
-                conf@1 {
-                        kernel = "kernel@1";
-                        fdt = "fdt@1";
+                default = "conf-1";
+                conf-1 {
+                        kernel = "kernel-1";
+                        fdt = "fdt-1";
                         %(ramdisk_config)s
                         %(loadables_config)s
                 };
@@ -410,7 +410,7 @@
 
         # Try a ramdisk
         with cons.log.section('Kernel + FDT + Ramdisk load'):
-            params['ramdisk_config'] = 'ramdisk = "ramdisk@1";'
+            params['ramdisk_config'] = 'ramdisk = "ramdisk-1";'
             params['ramdisk_load'] = 'load = <%#x>;' % params['ramdisk_addr']
             fit = make_fit(mkimage, params)
             cons.restart_uboot()
@@ -419,7 +419,7 @@
 
         # Configuration with some Loadables
         with cons.log.section('Kernel + FDT + Ramdisk load + Loadables'):
-            params['loadables_config'] = 'loadables = "kernel@2", "ramdisk@2";'
+            params['loadables_config'] = 'loadables = "kernel-2", "ramdisk-2";'
             params['loadables1_load'] = ('load = <%#x>;' %
                                          params['loadables1_addr'])
             params['loadables2_load'] = ('load = <%#x>;' %
diff --git a/test/py/tests/vboot_forge.py b/test/py/tests/vboot_forge.py
index 0fb7ef4..b41105b 100644
--- a/test/py/tests/vboot_forge.py
+++ b/test/py/tests/vboot_forge.py
@@ -376,12 +376,12 @@
     """
     Maliciously manipulates the structure to create a crafted FIT file
     """
-    # locate /images/kernel@1 (frankly, it just expects it to be the first one)
+    # locate /images/kernel-1 (frankly, it just expects it to be the first one)
     kernel_node = root[0][0]
     # clone it to save time filling all the properties
     fake_kernel = kernel_node.clone()
     # rename the node
-    fake_kernel.name = b'kernel@2'
+    fake_kernel.name = b'kernel-2'
     # get rid of signatures/hashes
     fake_kernel.children = []
     # NOTE: this simply replaces the first prop... either description or data
@@ -391,13 +391,13 @@
     root[0].children.append(fake_kernel)
 
     # modify the default configuration
-    root[1].props[0].value = b'conf@2\x00'
+    root[1].props[0].value = b'conf-2\x00'
     # clone the first (only?) configuration
     fake_conf = root[1][0].clone()
     # rename and change kernel and fdt properties to select the crafted kernel
-    fake_conf.name = b'conf@2'
-    fake_conf.props[0].value = b'kernel@2\x00'
-    fake_conf.props[1].value = b'fdt@1\x00'
+    fake_conf.name = b'conf-2'
+    fake_conf.props[0].value = b'kernel-2\x00'
+    fake_conf.props[1].value = b'fdt-1\x00'
     # insert the new configuration under /configurations
     root[1].children.append(fake_conf)