Re: [PATCH] driver core: platform: added arguments check for platform_device_add_resources()

[Greg KH]

On Tue, Mar 07, 2023 at 01:01:16PM +0800, Xujun Leng wrote:
> In the follow two cases, platform_device_add_resources() can lead an
> invalid address access:
> 1) If (!res && num > 0), pdev->resource will be set to NULL but
>    pdev->num_resources > 0, then a later platform_get_resource() will
>    cause invalid address access.
> 2) If (res && num == 0), because num == 0 cause kmalloc_slab() returns
>    ZERO_SIZE_PTR, then kmemdup() will copy data to the invalid address
>    ZERO_SIZE_PTR.
> 
> Signed-off-by: Xujun Leng <lengxujun2007@xxxxxxx>
> ---
>  drivers/base/platform.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 77510e4f47de..a060941c3076 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -606,6 +606,9 @@ int platform_device_add_resources(struct platform_device *pdev,
>  {
>  	struct resource *r = NULL;
>  
> +	if ((!res && num > 0) || (res && num == 0))
> +		return -EINVAL;

What driver is causing this check to fail today?  Shouldn't that be
fixed instead?

thanks,

greg k-h