linux-kernel - Re: [PATCH] arm64: disable KASAN for save_trace()

Open Source and information security mailing list archives

Date:   Sun, 11 Nov 2018 17:23:33 +0000
From:   Mark Rutland <mark.rutland@....com>
To:     Zhizhou Zhang <zhizhouzhang@...micro.com>
Cc:     catalin.marinas@....com, will.deacon@....com, mpatocka@...hat.com,
        alex.popov@...ux.com, labbott@...hat.com, panand@...hat.com,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        zhizhouzh@...il.com
Subject: Re: [PATCH] arm64: disable KASAN for save_trace()

On Sun, Nov 11, 2018 at 08:07:16PM +0800, Zhizhou Zhang wrote:
> save_trace() which is called from walk_stackframe() always try to
> read/write caller's stack. This results KASAN stack-out-of-bounds
> warning. So mute it.

The save_trace() function should never perform an out-of-bounds access on the
caller's stack, so this is papering over a bug elsewhere.

Can you please given an example report from KASAN?

Thanks,
Mark.

> 
> Signed-off-by: Zhizhou Zhang <zhizhouzhang@...micro.com>
> ---
>  arch/arm64/kernel/stacktrace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
> index 4989f7e..e93ca67 100644
> --- a/arch/arm64/kernel/stacktrace.c
> +++ b/arch/arm64/kernel/stacktrace.c
> @@ -107,7 +107,7 @@ struct stack_trace_data {
>  	unsigned int skip;
>  };
>  
> -static int save_trace(struct stackframe *frame, void *d)
> +static int __no_sanitize_address save_trace(struct stackframe *frame, void *d)
>  {
>  	struct stack_trace_data *data = d;
>  	struct stack_trace *trace = data->trace;
> -- 
> 2.7.4
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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