From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D88CC3A589 for ; Tue, 20 Aug 2019 22:28:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5557D22DA7 for ; Tue, 20 Aug 2019 22:28:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566340094; bh=yjV+99lCgsz4QxTJVtoV1wZiTnNI5b0nk4QnO2S7X34=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=YfeceHpAywXUqMfj5uBx3Rsh4mfZ8bon1Ul4yYbfx6rtXFw6+oT/LkAyYc4pCsODi 0cTGr5FXM8OBPCvnMVXkZ3upTvxxvr0MCGc+vlp0+3QkaoCgchE8eqbljhYji67wr3 aTaaNiZAI748k3VbVC+jJXvToddUpzxtd9HBLo2s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731021AbfHTW2M (ORCPT ); Tue, 20 Aug 2019 18:28:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:59734 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730638AbfHTW2L (ORCPT ); Tue, 20 Aug 2019 18:28:11 -0400 Received: from localhost (li1825-44.members.linode.com [172.104.248.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8BD1E22DA7; Tue, 20 Aug 2019 22:28:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566340091; bh=yjV+99lCgsz4QxTJVtoV1wZiTnNI5b0nk4QnO2S7X34=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r1H0O6aR3jggX0rVkU/AnvbNyHtfqnSyzrKrZyt871pAVYjnvl/LfcaEJP3COOCFC fLNvPUzb6bZ5Rv5KLWxrjjzYiF67zMAwTWjd50KTE5yaLqr4plgv1iE3cwpUy7CTsC bmJWc2qY+EK9PHIyouiuzNW76kjUnjFcGfHpPwRM= Date: Tue, 20 Aug 2019 15:28:05 -0700 From: Greg KH To: Charles.Hyde@dellteam.com Cc: linux-usb@vger.kernel.org, linux-acpi@vger.kernel.org, Mario.Limonciello@dell.com, oliver@neukum.org, netdev@vger.kernel.org, nic_swsd@realtek.com Subject: Re: [RFC 1/4] Add usb_get_address and usb_set_address support Message-ID: <20190820222805.GD8120@kroah.com> References: <1566339522507.45056@Dellteam.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1566339522507.45056@Dellteam.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, Aug 20, 2019 at 10:18:42PM +0000, Charles.Hyde@dellteam.com wrote: > +int usb_get_address(struct usb_device *dev, unsigned char * mac) > +{ > + int ret = -ENOMEM; > + unsigned char *tbuf = kmalloc(256, GFP_NOIO); On a technical level, why are you asking for 256 bytes here, and in the control message, yet assuming you will only get 6 back for a correct message? Shouldn't you be only asking for 6 bytes? > + > + if (!tbuf) > + return -ENOMEM; > + > + ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), > + USB_CDC_GET_NET_ADDRESS, > + USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, > + 0, USB_REQ_SET_ADDRESS, tbuf, 256, > + USB_CTRL_GET_TIMEOUT); > + if (ret == 6) > + memcpy(mac, tbuf, 6); > + > + kfree(tbuf); > + return ret; So if 100 is returned by the device (not likely, but let's say 7), then you return 7 bytes, yet you did not copy the data into the pointer given to you. SHouldn't you report a real error for when this happens (hint, it will.) thanks, greg k-h