linux-kernel - Re: [PATCH V2] x86/boot: Fix regression--secure boot info loss from bootparam sanitizing

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Date:   Mon, 2 Sep 2019 09:23:10 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     John S Gruber <JohnSGruber@...il.com>
Cc:     john.hubbard@...il.com, hpa@...or.com, jhubbard@...dia.com,
        linux-kernel@...r.kernel.org, mingo@...hat.com, tglx@...utronix.de,
        x86@...nel.org, stable@...r.kernel.org
Subject: Re: [PATCH V2] x86/boot: Fix regression--secure boot info loss from
 bootparam sanitizing

On Mon, Sep 02, 2019 at 12:00:54AM +0200, John S Gruber wrote:
> From: "John S. Gruber" <JohnSGruber@...il.com>
> 
> commit a90118c445cc ("x86/boot: Save fields explicitly, zero out everything
> else") now zeros the secure boot information passed by the boot loader or
> by the kernel's efi handover mechanism.  Include boot-params.secure_boot
> in the preserve field list.
> 
> I noted a change in my computers between running signed 5.3-rc4 and 5.3-rc6
> with signed kernels using the efi handoff protocol with grub. The kernel
> log message "Secure boot enabled" becomes "Secure boot could not be
> determined". The efi_main function in arch/x86/boot/compressed/eboot.c sets
> this field early but it is subsequently zeroed by the above referenced
> commit in the file arch/x86/include/asm/bootparam_utils.h
> 
> Fixes: commit a90118c445cc ("x86/boot: Save fields explicitly, zero
> out everything else")
> Signed-off-by: John S. Gruber <JohnSGruber@...il.com>
> ---
> 
> Adjusted the patch for John Hubbard's comments.
> 
>  arch/x86/include/asm/bootparam_utils.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/include/asm/bootparam_utils.h
> b/arch/x86/include/asm/bootparam_utils.h
> index 9e5f3c7..981fe92 100644
> --- a/arch/x86/include/asm/bootparam_utils.h
> +++ b/arch/x86/include/asm/bootparam_utils.h
> @@ -70,6 +70,7 @@ static void sanitize_boot_params(struct boot_params
> *boot_params)

gmail has managed to chew this patch:

checking file arch/x86/include/asm/bootparam_utils.h
patch: **** malformed patch at line 48: *boot_params)

See: https://www.kernel.org/doc/html/latest/process/email-clients.html#gmail-web-gui

You might find a better client in there if you wanna send more patches
in the future.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.