linux-kernel - Re: [patch 2/2] x86/mce/AMD: Make the init code more robust

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Date:   Tue, 27 Dec 2016 08:06:47 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Markus Trippelsdorf <markus@...ppelsdorf.de>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: Re: [patch 2/2] x86/mce/AMD: Make the init code more robust

On Mon, Dec 26, 2016 at 10:58:20PM +0100, Thomas Gleixner wrote:
> If mce_device_init() fails then the mce device pointer is NULL and the AMD
> mce code happily dereferences it.
> 
> Add a sanity check.
> 
> Reported-by: Markus Trippelsdorf <markus@...ppelsdorf.de>
> Reported-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> ---
>  arch/x86/kernel/cpu/mcheck/mce_amd.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> @@ -1182,6 +1182,9 @@ static int threshold_create_bank(unsigne
>  	const char *name = get_name(bank, NULL);
>  	int err = 0;
>  
> +	if (!dev)
> +		return -ENODEV;
> +
>  	if (is_shared_bank(bank)) {
>  		nb = node_to_amd_nb(amd_get_nb_id(cpu));

Acked-by: Borislav Petkov <bp@...e.de>

>From looking at that code, though, it could use some more involved
straightening later.

/me puts it on TODO list.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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