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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 99D22C3A5A2 for ; Fri, 20 Sep 2019 14:35:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A4DA2086A for ; Fri, 20 Sep 2019 14:35:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391704AbfITOe3 (ORCPT ); Fri, 20 Sep 2019 10:34:29 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36334 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388234AbfITOZH (ORCPT ); Fri, 20 Sep 2019 10:25:07 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqL-00051H-2x; Fri, 20 Sep 2019 15:25:05 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqH-0007yr-DA; Fri, 20 Sep 2019 15:25:01 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Greg Kroah-Hartman" , "Mauro Carvalho Chehab" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 120/132] media: smsusb: better handle optional alignment In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab commit a47686636d84eaec5c9c6e84bd5f96bed34d526d upstream. Most Siano devices require an alignment for the response. Changeset f3be52b0056a ("media: usb: siano: Fix general protection fault in smsusb") changed the logic with gets such aligment, but it now produces a sparce warning: drivers/media/usb/siano/smsusb.c: In function 'smsusb_init_device': drivers/media/usb/siano/smsusb.c:447:37: warning: 'in_maxp' may be used uninitialized in this function [-Wmaybe-uninitialized] 447 | dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); | ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~ The sparse message itself is bogus, but a broken (or fake) USB eeprom could produce a negative value for response_alignment. So, change the code in order to check if the result is not negative. Fixes: 31e0456de5be ("media: usb: siano: Fix general protection fault in smsusb") Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/media/usb/siano/smsusb.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -359,7 +359,7 @@ static int smsusb_init_device(struct usb struct smsdevice_params_t params; struct smsusb_device_t *dev; int i, rc; - int in_maxp = 0; + int align = 0; /* create device object */ dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL); @@ -379,14 +379,14 @@ static int smsusb_init_device(struct usb if (desc->bEndpointAddress & USB_DIR_IN) { dev->in_ep = desc->bEndpointAddress; - in_maxp = usb_endpoint_maxp(desc); + align = usb_endpoint_maxp(desc) - sizeof(struct sms_msg_hdr); } else { dev->out_ep = desc->bEndpointAddress; } } pr_debug("in_ep = %02x, out_ep = %02x\n", dev->in_ep, dev->out_ep); - if (!dev->in_ep || !dev->out_ep) { /* Missing endpoints? */ + if (!dev->in_ep || !dev->out_ep || align < 0) { /* Missing endpoints? */ smsusb_term_device(intf); return -ENODEV; } @@ -405,7 +405,7 @@ static int smsusb_init_device(struct usb /* fall-thru */ default: dev->buffer_size = USB2_BUFFER_SIZE; - dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); + dev->response_alignment = align; params.flags |= SMS_DEVICE_FAMILY2; break;