linux-kernel - Re: [PATCH v3 6/9] x86/microcode/AMD: verify patch section type for every such section

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Date:   Thu, 15 Mar 2018 17:31:25 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Maciej S. Szmigiero" <mail@...iej.szmigiero.name>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 6/9] x86/microcode/AMD: verify patch section type for
 every such section

On Tue, Mar 13, 2018 at 10:07:01PM +0100, Maciej S. Szmigiero wrote:
> We should check whether the patch section currently being processed is
> actually a patch section for each of them (not just the first one) in the
> late loader verify_and_add_patch() function, just like the early loader
> already does in parse_container() function.
> 
> Signed-off-by: Maciej S. Szmigiero <mail@...iej.szmigiero.name>
> ---
>  arch/x86/kernel/cpu/microcode/amd.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
> index 0f78200f2f6c..3ad23e72c2b0 100644
> --- a/arch/x86/kernel/cpu/microcode/amd.c
> +++ b/arch/x86/kernel/cpu/microcode/amd.c
> @@ -627,6 +627,11 @@ static int verify_and_add_patch(u8 family, u8 *fw, size_t leftover)
>  	if (leftover < SECTION_HDR_SIZE + sizeof(*mc_hdr))
>  		return leftover;
>  
> +	if (*(u32 *)fw != UCODE_UCODE_TYPE) {

Store that in a local var patch_type for better readability, while
you're touching that.

Also, for all your patch subject names for your next submission, start
the patch subject sentence with a capital letter:

Subject: [PATCH v3 6/9] x86/microcode/AMD: Verify patch section type for every such section

Thx.

-- 
Regards/Gruss,
    Boris.

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