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

[Sam Day]

On Thursday, 23 January 2025 at 14:29, Julien Masson <jmasson at baylibre.com> wrote:

> 
> On Thu 23 Jan 2025 at 14:28, Mattijs Korpershoek mkorpershoek at baylibre.com wrote:
> 
> > From: Aaron Kling webgeek1234 at gmail.com
> > 
> > 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 at gmail.com
> > Signed-off-by: Mattijs Korpershoek mkorpershoek at baylibre.com
> > ---
> > Thanks to Aaron for reporting this on the aosp-devs discord and for
> > fixing this.
> > ---
> > boot/image-android.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/boot/image-android.c b/boot/image-android.c
> > index 60a422dfb74a6c683b3cf9d2b19b3ad1dbd0d151..fa4e14ca4698e1dea105388dd2ea590024cafa58 100644
> > --- 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);
> > 
> > ---
> > base-commit: bc157bb6667ed97e33be8ce8436c28baa275b295
> > change-id: 20250113-kcmdline-extra-fix-509331e4d7f3
> > 
> > Best regards,
> > --
> > Mattijs Korpershoek mkorpershoek at baylibre.com
> 
> 
> Reviewed-by: Julien Masson jmasson at baylibre.com

Tested-by: Sam Day <me at samcday.com>