Subject: [PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

From: [email-masked] (Vinod Koul)
Date: Thu, 21 Mar 2013 15:16:09 +0530

On Fri, Mar 15, 2013 at 02:18:20PM +0530, Viresh Kumar wrote:
> In of_dma_controller_register() routine we are calling of_get_property() as an
> parameter to be32_to_cpup(). In case the property doesn't exist we will get a
> crash.
> 
> This patch changes this code to check if we got a valid property first and then
> runs be32_to_cpup() on it.
> 
> Signed-off-by: Viresh Kumar <[email-masked]>
> ---
> 
> My mails are broken, i have pushed this patch here:
I noticed you used git send-email. Usually it will send patch properly
independent of whatever MUA you use. So I have the patch and its applied now :)

--
~Vinod 
> 
> http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/heads/dma-of-fix
> 
>  drivers/dma/of-dma.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
> index 69d04d2..09c7ad1 100644
> --- a/drivers/dma/of-dma.c
> +++ b/drivers/dma/of-dma.c
> @@ -93,6 +93,7 @@ int of_dma_controller_register(struct device_node *np,
>  {
>  	struct of_dma	*ofdma;
>  	int		nbcells;
> +	const __be32	*prop;
>  
>  	if (!np || !of_dma_xlate) {
>  		pr_err("%s: not enough information provided\n", __func__);
> @@ -103,8 +104,11 @@ int of_dma_controller_register(struct device_node *np,
>  	if (!ofdma)
>  		return -ENOMEM;
>  
> -	nbcells = be32_to_cpup(of_get_property(np, "#dma-cells", NULL));
> -	if (!nbcells) {
> +	prop = of_get_property(np, "#dma-cells", NULL);
> +	if (prop)
> +		nbcells = be32_to_cpup(prop);
> +
> +	if (!prop || !nbcells) {
>  		pr_err("%s: #dma-cells property is missing or invalid\n",
>  		       __func__);
>  		kfree(ofdma);
> -- 
> 1.7.12.rc2.18.g61b472e
> 
>