Re: [PATCH] staging: gasket: sysfs: fix potential null dereference

[Greg KH]

On Tue, Jul 31, 2018 at 06:23:20PM +0300, Ivan Bornyakov wrote:
> Add handling of possible allocation failure.
> 
> Reported by smatch:
> 
>   drivers/staging/gasket/gasket_sysfs.c:105 put_mapping() error: potential null dereference 'files_to_remove'. (kcalloc returns null)
> 
> Signed-off-by: Ivan Bornyakov <brnkv.i1@xxxxxxxxx>
> ---
>  drivers/staging/gasket/gasket_sysfs.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c
> index ef4eca02afa6..682e5c21f203 100644
> --- a/drivers/staging/gasket/gasket_sysfs.c
> +++ b/drivers/staging/gasket/gasket_sysfs.c
> @@ -101,6 +101,12 @@ static void put_mapping(struct gasket_sysfs_mapping *mapping)
>  		files_to_remove = kcalloc(num_files_to_remove,
>  					  sizeof(*files_to_remove),
>  					  GFP_KERNEL);
> +		if (!files_to_remove) {
> +			pr_err("%s: can't allocate memory\n", __func__);

kcalloc failing will print something, no need to do it again here.

thanks,

greg k-h