Re: [PATCH v2] usb: storage: add error handling for kcalloc

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jun 14, 2018 at 09:29:11PM +0800, Zhouyang Jia wrote:
> When kcalloc fails, the lack of error-handling code may
> cause unexpected results.
> 
> This patch adds error-handling code after calling kcalloc.
> 
> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
> Acked-by: Alan Stern <stern@rowland.harvard.edu>
> ---
> v1->v2:
> - Remove pr_warn statement.
> ---
>  drivers/usb/storage/alauda.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
> index 900591d..4e17609 100644
> --- a/drivers/usb/storage/alauda.c
> +++ b/drivers/usb/storage/alauda.c
> @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us)
>  		+ MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift);
>  	MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO);
>  	MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO);
> +	if ((MEDIA_INFO(us).pba_to_lba == NULL)
> +		|| (MEDIA_INFO(us).lba_to_pba == NULL))
> +		return USB_STOR_TRANSPORT_ERROR;

You just leaked memory if only one of these succeeded :(