[PATCH] LoongArch: kexec: Initialize kexec_buf struct

[Huacai Chen]

Applied, thanks.

Huacai

On Fri, Oct 24, 2025 at 2:38 PM Youling Tang <youling.tang at linux.dev> wrote:
>
> From: Youling Tang <tangyouling at kylinos.cn>
>
> The kexec_buf structure was previously declared without initialization.
> commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
> added a field that is always read but not consistently populated by all
> architectures. This un-initialized field will contain garbage.
>
> This is also triggering a UBSAN warning when the uninitialized data was
> accessed:
>
>         ------------[ cut here ]------------
>         UBSAN: invalid-load in ./include/linux/kexec.h:210:10
>         load of value 252 is not a valid value for type '_Bool'
>
> Zero-initializing kexec_buf at declaration ensures all fields are
> cleanly set, preventing future instances of uninitialized memory being
> used.
>
> Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
> Link: https://lore.kernel.org/r/20250827-kbuf_all-v1-2-1df9882bb01a@debian.org
> Signed-off-by: Youling Tang <tangyouling at kylinos.cn>
> ---
>  arch/loongarch/kernel/kexec_efi.c          | 2 +-
>  arch/loongarch/kernel/kexec_elf.c          | 2 +-
>  arch/loongarch/kernel/machine_kexec_file.c | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/loongarch/kernel/kexec_efi.c b/arch/loongarch/kernel/kexec_efi.c
> index 45121b914f8f..5ee78ebb1546 100644
> --- a/arch/loongarch/kernel/kexec_efi.c
> +++ b/arch/loongarch/kernel/kexec_efi.c
> @@ -42,7 +42,7 @@ static void *efi_kexec_load(struct kimage *image,
>  {
>         int ret;
>         unsigned long text_offset, kernel_segment_number;
> -       struct kexec_buf kbuf;
> +       struct kexec_buf kbuf = {};
>         struct kexec_segment *kernel_segment;
>         struct loongarch_image_header *h;
>
> diff --git a/arch/loongarch/kernel/kexec_elf.c b/arch/loongarch/kernel/kexec_elf.c
> index 97b2f049801a..1b6b64744c7f 100644
> --- a/arch/loongarch/kernel/kexec_elf.c
> +++ b/arch/loongarch/kernel/kexec_elf.c
> @@ -59,7 +59,7 @@ static void *elf_kexec_load(struct kimage *image,
>         int ret;
>         unsigned long text_offset, kernel_segment_number;
>         struct elfhdr ehdr;
> -       struct kexec_buf kbuf;
> +       struct kexec_buf kbuf = {};
>         struct kexec_elf_info elf_info;
>         struct kexec_segment *kernel_segment;
>
> diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
> index dda236b51a88..fb57026f5f25 100644
> --- a/arch/loongarch/kernel/machine_kexec_file.c
> +++ b/arch/loongarch/kernel/machine_kexec_file.c
> @@ -143,7 +143,7 @@ int load_other_segments(struct kimage *image,
>         unsigned long initrd_load_addr = 0;
>         unsigned long orig_segments = image->nr_segments;
>         char *modified_cmdline = NULL;
> -       struct kexec_buf kbuf;
> +       struct kexec_buf kbuf = {};
>
>         kbuf.image = image;
>         /* Don't allocate anything below the kernel */
> --
> 2.43.0
>