Re: [PATCH] DMA: OF: Check properties value before runningbe32_to_cpup() on it

From: Vinod Koul
Date: Thu Mar 21 2013 - 06:11:19 EST


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 <viresh.kumar@xxxxxxxxxx>
> ---
>
> 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
>
>
--
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