image-fit: use real size of fit image

PATCH Superseded Daniel Brát 1 participant 1 message Jul 18, 2022

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Daniel Brát

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2022-07-18 19:28 UTC #0 lore raw

PATCH 1/1 image-fit: use real size of fit image

The real size of the fit image might be significantly smaller than it may appear to be based on the specified filename. For example, if path to raw disk partition is passed (eg. /dev/disk0.1), the size of the partition itself might be several times larger than the fit image it contains at the moment (so it has headroom for possible future image size changes).
This modification uses the fdt header field 'totalsize' to read-in only what is needed.

Signed-off-by Daniel Brát <[email protected]>

---
 common/image-fit.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

common/image-fit.c +24 -3

index a410632d70..24e63f9a72 100644
@@ -774,13 +774,18 @@ struct fit_handle *fit_open_buf(const void *buf, size_t size, bool verbose,
 				enum bootm_verify verify)
 {
 	struct fit_handle *handle;
+	struct fdt_header *header;
 	int ret;
 
+	if (size < sizeof(*header))
+		return ERR_PTR(-EINVAL);
+
+	header = (struct fdt_header*)buf;
 	handle = xzalloc(sizeof(struct fit_handle));
 
 	handle->verbose = verbose;
 	handle->fit = buf;
-	handle->size = size;
+	handle->size = (size_t)header->totalsize;
 	handle->verify = verify;
 
 	ret = fit_do_open(handle);

@@ -807,15 +812,31 @@ struct fit_handle *fit_open(const char *filename, bool verbose,
 			    enum bootm_verify verify)
 {
 	struct fit_handle *handle;
-	int ret;
+	struct fdt_header header;
+	int fd, ret;
 
 	handle = xzalloc(sizeof(struct fit_handle));
 
 	handle->verbose = verbose;
 	handle->verify = verify;
 
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		pr_err("unable to open %s: %s\n", filename, strerror(errno));
+		return ERR_PTR(-errno);
+	}
+
+	ret = read_full(fd, &header, sizeof(header));
+	if (ret < 0) {
+		close(fd);
+		pr_err("unable to read %s: %s\n", filename, strerror(errno));
+		return ERR_PTR(-errno);
+	}
+
+	close(fd);
+
 	ret = read_file_2(filename, &handle->size, &handle->fit_alloc,
-			  FILESIZE_MAX);
+			  header.totalsize);
 	if (ret) {
 		pr_err("unable to read %s: %s\n", filename, strerror(-ret));
 		return ERR_PTR(ret);

Signature · 1 line

2.17.1