boot: android: Check kcmdline's for NULL in android_image_get_kernel()

kcmdline and kcmdline_extra strings can be NULL. In that case, we still
read the content from 0x00000 and pass that to the kernel, which is
completely wrong.

Fix android_image_get_kernel() to check for NULL before checking if
they are empty strings.

Fixes: 53a0ddb6d3be ("boot: android: fix extra command line support")
Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
Reviewed-by: Nicolas Belin <nbelin@baylibre.com>
Reviewed-by: Julien Masson <jmasson@baylibre.com>
Tested-by: Sam Day <me@samcday.com>
Link: https://lore.kernel.org/r/20250113-kcmdline-extra-fix-v1-1-03cc9c039159@baylibre.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

diff --git a/boot/image-android.c b/boot/image-android.c
index 60a422d..fa4e14c 100644 (file)
--- a/boot/image-android.c
+++ b/boot/image-android.c
@@ -337,12 +337,12 @@ int android_image_get_kernel(const void *hdr,
        if (bootargs)
                len += strlen(bootargs);
 
-       if (*img_data.kcmdline) {
+       if (img_data.kcmdline && *img_data.kcmdline) {
                printf("Kernel command line: %s\n", img_data.kcmdline);
                len += strlen(img_data.kcmdline) + (len ? 1 : 0); /* +1 for extra space */
        }
 
-       if (*img_data.kcmdline_extra) {
+       if (img_data.kcmdline_extra && *img_data.kcmdline_extra) {
                printf("Kernel extra command line: %s\n", img_data.kcmdline_extra);
                len += strlen(img_data.kcmdline_extra) + (len ? 1 : 0); /* +1 for extra space */
        }
@@ -357,13 +357,13 @@ int android_image_get_kernel(const void *hdr,
        if (bootargs)
                strcpy(newbootargs, bootargs);
 
-       if (*img_data.kcmdline) {
+       if (img_data.kcmdline && *img_data.kcmdline) {
                if (*newbootargs) /* If there is something in newbootargs, a space is needed */
                        strcat(newbootargs, " ");
                strcat(newbootargs, img_data.kcmdline);
        }
 
-       if (*img_data.kcmdline_extra) {
+       if (img_data.kcmdline_extra && *img_data.kcmdline_extra) {
                if (*newbootargs) /* If there is something in newbootargs, a space is needed */
                        strcat(newbootargs, " ");
                strcat(newbootargs, img_data.kcmdline_extra);