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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190902072310.GA9605@zn.tnic>
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.