Re: [PATCH][V2] usb: isp1760: fix null dereference if kzalloc returns null

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 06/02/2015 06:41 PM, Laurent Pinchart wrote:

>>> From: Colin Ian King <colin.king@canonical.com>

>>> If kzalloc returns null then isp1760_ep_alloc_request performs
>>> a null pointer dereference on req. Check for null to avoid this.

>> I told you there's no dereference and yet you're repeating it again. :-(

> How about

> "isp1760_ep_alloc_request allocates a structure with kzalloc without checking
> for NULL and then returns a pointer to one of the structure fields. As the
> field happens to be the first in the structure the caller can properly check
> for NULL, but this is risky if the structure layout is changed later. Add an
> explicit NULL check for the kzalloc return value."

    Fine with me! Thanks, Laurent. :-)

>>> a null pointer dereference on req. Check for null to avoid this.

>>> Detected with smatch static analysis:

>>> drivers/usb/isp1760/isp1760-udc.c:816 isp1760_ep_alloc_request()

>>>     error: potential null dereference 'req'.  (kzalloc returns null)

>>> Signed-off-by: Colin Ian King <colin.king@canonical.com>

WBR, Sergei