Re: [PATCH] MFD: prevent null pointer dereference in mfd_add_device

[Florian Fainelli <florian@openwrt.org>]

Hi Samuel,

I just saw that your for-next branch contains the proper fix, this patch can be 
discarded.

Le samedi 15 mai 2010 21:57:10, Florian Fainelli a écrit :
> If a driver calls mfd_add_device with a NULL argument for the mem_base
>  resource we will end up dereferencing it without checking for its validity
>  here: res[r].start = mem_base->start cell->resources[r].start; (line 53 of
>  mfd-core.c)
> 
> This patch adds the checking on the mem_base argument and bails out
>  accordingly if it is NULL.
> 
> Signed-off-by: Florian Fainelli <florian@openwrt.org>
> CC: stable@kernel.org
> ---
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 8ffbb7a..f890b27 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -49,6 +49,8 @@ static int mfd_add_device(struct device *parent, int id,
> 
>  		/* Find out base to use */
>  		if (cell->resources[r].flags & IORESOURCE_MEM) {
> +			if (!mem_base)
> +				goto fail_res;
>  			res[r].parent = mem_base;
>  			res[r].start = mem_base->start +
>  				cell->resources[r].start;
>