From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755181Ab2ISIF1 (ORCPT ); Wed, 19 Sep 2012 04:05:27 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:53455 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507Ab2ISIFJ (ORCPT ); Wed, 19 Sep 2012 04:05:09 -0400 Message-ID: <50597CAD.7010801@suse.cz> Date: Wed, 19 Sep 2012 10:05:01 +0200 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20120904 Thunderbird/16.0 MIME-Version: 1.0 To: Kevin Daughtridge CC: Jiri Kosina , linux-input@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Henrik Rydberg Subject: Re: [PATCH v2] HID: leave dev_rdesc unmodified and use it for comparisons References: <50592FB1.7000800@kdau.com> In-Reply-To: <50592FB1.7000800@kdau.com> X-Enigmail-Version: 1.5a1pre Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/19/2012 04:36 AM, Kevin Daughtridge wrote: > --- a/drivers/hid/hid-core.c > +++ b/drivers/hid/hid-core.c > @@ -775,12 +775,14 @@ int hid_open_report(struct hid_device *d > return -ENODEV; > size = device->dev_rsize; > > + start = kmemdup(start, size, GFP_KERNEL); > + if (start == NULL) > + return -ENOMEM; > + > if (device->driver->report_fixup) > start = device->driver->report_fixup(device, start, &size); > > - device->rdesc = kmemdup(start, size, GFP_KERNEL); > - if (device->rdesc == NULL) > - return -ENOMEM; > + device->rdesc = start; > device->rsize = size; AFAICS this is incorrect. Some drivers return pointers to their own static structure from their .report_fixup. Hence there are two problems: * leak, because kmemdup'ped start is never freed * invalid free -- kfree(device->rdesc) will try to free a static structure regards, -- js suse labs