[PATCH] efi_loader: Assure fitImage from capsule is used from 8-byte aligned address

[Ilias Apalodimas]

On Wed, 19 Nov 2025 at 19:34, Marek Vasut <marek.vasut at mailbox.org> wrote:
>
> On 11/18/25 2:56 PM, Ilias Apalodimas wrote:
>
> Hello Ilias,
>
> sorry for my slow response, I am buried under emails.

No worries

>
> >>>> +               img = memalign(8, image_size);
> >>>> +               if (!img)
> >>>> +                       return EFI_EXIT(EFI_BAD_BUFFER_SIZE);
> >>>> +               memcpy(img, image, image_size);
> >>>> +       } else {
> >>>> +               img = (void *)image;
> >>>> +       }
> >>>> +
> >>>> +       ret = fit_update(img);
> >>>> +
> >>>> +       if ((uintptr_t)image & 7)
> >>>> +               free(img);
> >>>
> >>> Initialize img to NULL and make the check a bit simpler to read (or
> >>> get rid of it overall)
> >> This part ^ I do not understand. The img variable is used by
> >> fit_update(img) , where should it be initialized to NULL ?
> >
> > The patch might be misleading since it doesn't show the entire
> > function. But from what I saw 'img' is only initialized when
> > 'if ((uintptr_t)image & 7)' is true. you can initialize img to NULL on
> > the declaration and just check for that.
>
> The 'img' is always initialized, see this:
>
> "
> +       if ((uintptr_t)image & 7) {
> +               img = memalign(8, image_size);
>                  ^^^ ----------------------- Here it is initialized
> +               if (!img)
> +                       return EFI_EXIT(EFI_BAD_BUFFER_SIZE);
> +               memcpy(img, image, image_size);
> +       } else {
> +               img = (void *)image;
>                  ^^^ ----------------------- Here it is initialized too
> +       }
> "

Which I somehow missed reading the patch...

Thanks
/Ilias