Re: [RFC][PATCH 2/3] staging: ion: Fix possible null pointer dereference

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Dec 16, 2013 at 01:32:43PM -0800, John Stultz wrote:
> The kbuild test robot reported:
> 
> drivers/staging/android/ion/ion_system_heap.c:122 alloc_largest_available() error: potential null dereference 'info'.  (kmalloc returns null)
> 
> Where the pointer returned from kmalloc goes unchecked for failure.
> 
> This patch adds a simple check for a null return, and handles the error.
> 
> XXX: Not sure if continue or 'return NULL' is the right thing to do.
> 
> Cc: Colin Cross <ccross@android.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>
> Cc: Android Kernel Team <kernel-team@android.com>
> Cc: kbuild test robot <fengguang.wu@intel.com>
> Reported-by: kbuild test robot <fengguang.wu@intel.com>
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>  drivers/staging/android/ion/ion_system_heap.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
> index 144b2272..cc2e4da 100644
> --- a/drivers/staging/android/ion/ion_system_heap.c
> +++ b/drivers/staging/android/ion/ion_system_heap.c
> @@ -119,6 +119,11 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
>  			continue;
>  
>  		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
> +		if(!info) {

Please don't add new coding style issues to staging drivers, the goal is
to clean them up, not make more mess :)

Care to resend this when you have figured out the XXX: line above?

thanks,

greg k-h