From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422708Ab2CPLOo (ORCPT ); Fri, 16 Mar 2012 07:14:44 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:56819 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965483Ab2CPLOn convert rfc822-to-8bit (ORCPT ); Fri, 16 Mar 2012 07:14:43 -0400 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes To: "Felipe Balbi" , "Yongsul Oh" Cc: "Greg Kroah-Hartman" , "Michal Nazarewicz" , "Sergei Shtylyov" , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] USB: Gadget: Composite: Added error handling codes to prevent a memory leak case when the configuration's bind function failed References: <1331879235-2910-1-git-send-email-yongsul96.oh@samsung.com> Date: Fri, 16 Mar 2012 12:14:37 +0100 MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT From: "Michal Nazarewicz" Message-ID: In-Reply-To: <1331879235-2910-1-git-send-email-yongsul96.oh@samsung.com> User-Agent: Opera Mail/11.61 (Linux) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 16 Mar 2012 07:27:15 +0100, Yongsul Oh wrote: > In some usb gadget driver, (for example usb gadget serial driver(serial.c), s/usb/USB/g s/gadget driver/composite gadget drivers/ I also don't think the list of examples is necessary here. Maybe just a list file names? My personal opinion, others may disagree though. Also, comma should go after the closing paren. > multifunction composite driver(multi,c), nokia composite gadget driver(nokia.c), > HID composite driver(hid.c), CDC composite driver(cdc2.c)..) the configuration's > bind function by called the 'usb_add_config()' has multiple bind config functions s/by called the/called by the/ s/has/calls/ > for each functionality. (for example cdc2 configuration bind function -'cdc_do_config()' s/functions for each functionality/functions, one for each USB functionality/ > has two functionality bind config functions -'ecm_bind_config()' & 'acm_bind_config()' > in CDC composite driver.) > > In each functionality bind config function, new instance for each functionality is s/for each functionality// > allocated & initialized by 'kzalloc()' and finally the new instance is added by s/& initialized by 'kzalloc()' and finally the new instance/and/ > 'usb_add_function()'. After 'usb_add_function' state, already created the instance > is only handled by it's configuration & freed from functionality unbind function. I'm not sure what you meant by this last sentence. > So, If an error occurred during the second functionality bind config state, s/If/if/ s/state// > (for example an error occurred at 'acm_bind_config()' after succeeding of > 'ecm_bind_function()') the created instance by 'acm_bind_config()' s/the created instance by 'acm_bind_config()'/the instance created by acm_bind_config()/ > cannot be freed. And it makes memory leak situation. s/freed. And it makes memory leak situation./freed creating a memory leak./ > This patch fixes this issue s/issue/issue./ Also, drop apostrophes around function names. It looks weird. > Signed-off-by: Yongsul Oh Acked-by: Michal Nazarewicz Also, like written previously, I think there might be memory leak in other error recovery paths as well. If you could take a look whether I'm right, that would be awesome. > --- > drivers/usb/gadget/composite.c | 13 +++++++++++++ > 1 files changed, 13 insertions(+), 0 deletions(-) > > diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c > index baaebf2..4cb1801 100644 > --- a/drivers/usb/gadget/composite.c > +++ b/drivers/usb/gadget/composite.c > @@ -737,6 +737,19 @@ int usb_add_config(struct usb_composite_dev *cdev, > status = bind(config); > if (status < 0) { > + while (!list_empty(&config->functions)) { > + struct usb_function *f; > + > + f = list_first_entry(&config->functions, > + struct usb_function, list); > + list_del(&f->list); > + if (f->unbind) { > + DBG(cdev, "unbind function '%s'/%p\n", > + f->name, f); > + f->unbind(config, f); > + /* may free memory for "f" */ > + } > + } > list_del(&config->list); > config->cdev = NULL; > } else { -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz (o o) ooo +------------------ooO--(_)--Ooo--