[PATCH 1/1] tools: mkimage: validate image references in FIT configurations

[Aristo Chen]

When parsing a FIT image source (ITS), mkimage does not currently check
whether the image names referenced in the /configurations section (e.g.
"kernel", "fdt", "ramdisk", "loadables") actually exist in the /images
node.

This patch introduces a validation step during FIT import that iterates
over each configuration and verifies that all referenced image names are
defined under /images. If a missing image is detected, an appropriate
error is reported and mkimage exits with FDT_ERR_NOTFOUND.

This ensures that configuration integrity is validated at build time.

Signed-off-by: Aristo Chen <aristo.chen at canonical.com>
---
 tools/fit_image.c | 48 +++++++++++++++++++++++++++++++++++++++++++++--
 tools/mkimage.c   |  7 ++++++-
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/tools/fit_image.c b/tools/fit_image.c
index caed8d5f901..02b9c9b5855 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -627,6 +627,7 @@ static int fit_import_data(struct image_tool_params *params, const char *fname)
 	struct stat sbuf;
 	int ret;
 	int images;
+	int confs;
 	int node;
 
 	fd = mmap_fdt(params->cmdname, fname, 0, &old_fdt, &sbuf, false, false);
@@ -695,6 +696,49 @@ static int fit_import_data(struct image_tool_params *params, const char *fname)
 		}
 	}
 
+	confs = fdt_path_offset(fdt, FIT_CONFS_PATH);
+
+	for (node = fdt_first_subnode(fdt, confs);
+	     node >= 0;
+	     node = fdt_next_subnode(fdt, node)) {
+		static const char * const props[] = { FIT_KERNEL_PROP,
+						      FIT_RAMDISK_PROP,
+						      FIT_FDT_PROP,
+						      FIT_LOADABLE_PROP };
+
+		for (int i = 0; i < ARRAY_SIZE(props); i++) {
+			const char *list;
+			int len = 0;
+			int offset = 0;
+
+			list = fdt_getprop(fdt, node, props[i], &len);
+			if (!list)
+				continue;
+
+			// Some properties (like loadables) are stringlists
+			while (offset < len) {
+				const char *img_name = list + offset;
+				char img_path[256];
+
+				offset += strlen(img_name) + 1;
+				snprintf(img_path, sizeof(img_path), "%s/%s", FIT_IMAGES_PATH,
+					 img_name);
+
+				int img = fdt_path_offset(fdt, img_path);
+
+				if (img < 0) {
+					const char *conf_name = fdt_get_name(fdt, node, NULL);
+
+					fprintf(stderr,
+						"Error: configuration '%s' references undefined image '%s'\n",
+						conf_name, img_name);
+					ret = FDT_ERR_NOTFOUND;
+					goto err_munmap;
+				}
+			}
+		}
+	}
+
 	munmap(old_fdt, sbuf.st_size);
 
 	/* Close the old fd so we can re-use it. */
@@ -750,7 +794,7 @@ static int fit_handle_file(struct image_tool_params *params)
 	char bakfile[MKIMAGE_MAX_TMPFILE_LEN + 4] = {0};
 	char cmd[MKIMAGE_MAX_DTC_CMDLINE_LEN];
 	size_t size_inc;
-	int ret;
+	int ret = EXIT_FAILURE;
 
 	/* Flattened Image Tree (FIT) format  handling */
 	debug ("FIT format handling\n");
@@ -854,7 +898,7 @@ static int fit_handle_file(struct image_tool_params *params)
 err_system:
 	unlink(tmpfile);
 	unlink(bakfile);
-	return -1;
+	return ret;
 }
 
 /**
diff --git a/tools/mkimage.c b/tools/mkimage.c
index 2954626a283..361711c53b2 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -519,8 +519,13 @@ int main(int argc, char **argv)
 			 */
 			retval = tparams->fflag_handle(&params);
 
-		if (retval != EXIT_SUCCESS)
+		if (retval != EXIT_SUCCESS) {
+			if (retval == FDT_ERR_NOTFOUND) {
+				// Already printed error, exit cleanly
+				exit(EXIT_FAILURE);
+			}
 			usage("Bad parameters for FIT image type");
+		}
 	}
 
 	if (params.lflag || params.fflag) {
-- 
2.43.0