From patchwork Fri May 14 14:24:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 439702 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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY autolearn=unavailable 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 9149AC433B4 for ; Fri, 14 May 2021 14:26:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 534C9611CC for ; Fri, 14 May 2021 14:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231712AbhENO1t (ORCPT ); Fri, 14 May 2021 10:27:49 -0400 Received: from mx0a-00069f02.pphosted.com ([205.220.165.32]:14674 "EHLO mx0a-00069f02.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229942AbhENO1s (ORCPT ); Fri, 14 May 2021 10:27:48 -0400 Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 14EEMNDg027629; Fri, 14 May 2021 14:25:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=5bl1zmUBree67gp8ksHVfQp53E6olxx+qbucqo8ZA7c=; b=gxJi051NTXSXHm8q738zmdTQ8mihP1X1ixC0KXc1vk5xe9oOS22ZiTTpFgLC4MZp06Mj pRQHwWI/dFOOCbV2qKantlsRmzlNOAFCo6IsrtoQlFv0kty0ZbHIVO0eJ6l4P+gAtJne J/pyXFgp47RHZaDepiXX8bdpoe5fha0OAeE0LMT9NUn2GP4sI0t5ydZWFyjTQ0eHOME3 ohAaotzy1GkXSbR5w7xGCe3eiftiad5QTioDQcPpDX7cqVa5x6bKaTaBeIS3mWmlx4jm f0TwrzjKu0VuSuOTb2uRWjkBQr5cGRcQCmkfSDeAwuG6qBF9wqfbvGSzjVOxOL8GLFfO UQ== Received: from oracle.com (aserp3030.oracle.com [141.146.126.71]) by mx0b-00069f02.pphosted.com with ESMTP id 38gpqsrq3b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 14 May 2021 14:25:04 +0000 Received: from aserp3030.oracle.com (aserp3030.oracle.com [127.0.0.1]) by pps.podrdrct (8.16.0.36/8.16.0.36) with SMTP id 14EEO5p2106870; Fri, 14 May 2021 14:25:03 GMT Received: from pps.reinject (localhost [127.0.0.1]) by aserp3030.oracle.com with ESMTP id 38gppq53yg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 14 May 2021 14:25:03 +0000 Received: from aserp3030.oracle.com (aserp3030.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 14EEM3bl103577; Fri, 14 May 2021 14:25:02 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 38gppq53wp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 14 May 2021 14:25:02 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 14EEOumt008995; Fri, 14 May 2021 14:24:57 GMT Received: from mwanda (/102.36.221.92) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 14 May 2021 07:24:56 -0700 Date: Fri, 14 May 2021 17:24:48 +0300 From: Dan Carpenter To: "David S. Miller" , Johan Hovold Cc: Jakub Kicinski , Oliver Neukum , Anirudh Rayabharam , Johan Hovold , Zheng Yongjun , Geert Uytterhoeven , Emil Renner Berthing , Rustam Kovhaev , linux-usb@vger.kernel.org, netdev@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH v2 net] net: hso: check for allocation failure in hso_create_bulk_serial_device() Message-ID: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email haha only kidding X-Proofpoint-GUID: iw5OUc9nxGpX4DRnwmKRtU1O-Z93NsTo X-Proofpoint-ORIG-GUID: iw5OUc9nxGpX4DRnwmKRtU1O-Z93NsTo Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In current kernels, small allocations never actually fail so this patch shouldn't affect runtime. Originally this error handling code written with the idea that if the "serial->tiocmget" allocation failed, then we would continue operating instead of bailing out early. But in later years we added an unchecked dereference on the next line. serial->tiocmget->serial_state_notification = kzalloc(); ^^^^^^^^^^^^^^^^^^ Since these allocations are never going fail in real life, this is mostly a philosophical debate, but I think bailing out early is the correct behavior that the user would want. And generally it's safer to bail as soon an error happens. Fixes: af0de1303c4e ("usb: hso: obey DMA rules in tiocmget") Signed-off-by: Dan Carpenter Reviewed-by: Johan Hovold --- v2: Do more extensive clean up. As Johan pointed out the comments and later NULL checks can be removed. drivers/net/usb/hso.c | 37 ++++++++++++++++++------------------- 1 file changed, 18 insertions(+), 19 deletions(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index 3ef4b2841402..260f850d69eb 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2618,29 +2618,28 @@ static struct hso_device *hso_create_bulk_serial_device( num_urbs = 2; serial->tiocmget = kzalloc(sizeof(struct hso_tiocmget), GFP_KERNEL); + if (!serial->tiocmget) + goto exit; serial->tiocmget->serial_state_notification = kzalloc(sizeof(struct hso_serial_state_notification), GFP_KERNEL); - /* it isn't going to break our heart if serial->tiocmget - * allocation fails don't bother checking this. - */ - if (serial->tiocmget && serial->tiocmget->serial_state_notification) { - tiocmget = serial->tiocmget; - tiocmget->endp = hso_get_ep(interface, - USB_ENDPOINT_XFER_INT, - USB_DIR_IN); - if (!tiocmget->endp) { - dev_err(&interface->dev, "Failed to find INT IN ep\n"); - goto exit; - } - - tiocmget->urb = usb_alloc_urb(0, GFP_KERNEL); - if (tiocmget->urb) { - mutex_init(&tiocmget->mutex); - init_waitqueue_head(&tiocmget->waitq); - } else - hso_free_tiomget(serial); + if (!serial->tiocmget->serial_state_notification) + goto exit; + tiocmget = serial->tiocmget; + tiocmget->endp = hso_get_ep(interface, + USB_ENDPOINT_XFER_INT, + USB_DIR_IN); + if (!tiocmget->endp) { + dev_err(&interface->dev, "Failed to find INT IN ep\n"); + goto exit; } + + tiocmget->urb = usb_alloc_urb(0, GFP_KERNEL); + if (tiocmget->urb) { + mutex_init(&tiocmget->mutex); + init_waitqueue_head(&tiocmget->waitq); + } else + hso_free_tiomget(serial); } else num_urbs = 1;