On Fri, Mar 22, 2024 at 01:08:45AM +0000, Oleksandr Tymoshenko wrote:
> Check if get_next_variable() is actually valid pointer before
> calling it. In kdump kernel this method is set to NULL that causes
> panic during the kexec-ed kernel boot.
>
> Tested with QEMU and OVMF firmware.
Sounds like you want a Fixes and CC stable tag here as well.
> Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
> ---
> drivers/firmware/efi/efi.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 8859fb0b006d..800b85807a02 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -203,6 +203,8 @@ static bool generic_ops_supported(void)
>
> name_size = sizeof(name);
>
> + if (efi.get_next_variable == NULL)
> + return false;
Please move this check above the name_size initialisation and make sure
you have a new line before and after.
I'd also suggest rewriting this as:
if (!efi.get_next_variable)
return false;
> status = efi.get_next_variable(&name_size, &name, &guid);
> if (status == EFI_UNSUPPORTED)
> return false;
Johan