image: Fix potentially uninitialized data variable

In case fitImage support is disabled, and image_locate_script() is
passed a fitImage, then the 'data' variable is used uninitialized.
Drop into the default: branch of the switch-case statement and do
not return the uninitialized data, and do not modify the return
pointer either, just print an error message.

Reported by clang build:
"
$ make HOSTCC=clang CC=clang KCFLAGS=-Werror sandbox64_defconfig && make HOSTCC=clang CC=clang KCFLAGS=-Werror
...
boot/image-board.c:1006:7: error: variable 'data' is used uninitialized whenever switch case is taken [-Werror,-Wsometimes-uninitialized]
        case IMAGE_FORMAT_LEGACY:
             ^~~~~~~~~~~~~~~~~~~
include/image.h:608:29: note: expanded from macro 'IMAGE_FORMAT_LEGACY'
                                ^~~~
boot/image-board.c:1128:19: note: uninitialized use occurs here
        *datap = (char *)data;
                         ^~~~
boot/image-board.c:1001:11: note: initialize the variable 'data' to silence this warning
        u32 *data;
                 ^
                  = NULL
"

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/boot/image-board.c b/boot/image-board.c
index 25b60ec..9bf7082 100644 (file)
--- a/boot/image-board.c
+++ b/boot/image-board.c
@@ -1004,7 +1004,9 @@ int image_locate_script(void *buf, int size, const char *fit_uname,
 
        switch (genimg_get_format(buf)) {
        case IMAGE_FORMAT_LEGACY:
-               if (IS_ENABLED(CONFIG_LEGACY_IMAGE_FORMAT)) {
+               if (!IS_ENABLED(CONFIG_LEGACY_IMAGE_FORMAT)) {
+                       goto exit_image_format;
+               } else {
                        hdr = buf;
 
                        if (!image_check_magic(hdr)) {
@@ -1047,7 +1049,9 @@ int image_locate_script(void *buf, int size, const char *fit_uname,
                }
                break;
        case IMAGE_FORMAT_FIT:
-               if (IS_ENABLED(CONFIG_FIT)) {
+               if (!IS_ENABLED(CONFIG_FIT)) {
+                       goto exit_image_format;
+               } else {
                        fit_hdr = buf;
                        if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
                                puts("Bad FIT image format\n");
@@ -1121,12 +1125,15 @@ fallback:
                }
                break;
        default:
-               puts("Wrong image format for \"source\" command\n");
-               return -EPERM;
+               goto exit_image_format;
        }
 
        *datap = (char *)data;
        *lenp = len;
 
        return 0;
+
+exit_image_format:
+       puts("Wrong image format for \"source\" command\n");
+       return -EPERM;
 }