From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966321AbdKPR4y (ORCPT ); Thu, 16 Nov 2017 12:56:54 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:38190 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965685AbdKPRvh (ORCPT ); Thu, 16 Nov 2017 12:51:37 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrey Konovalov , Dmitry Torokhov , Ben Hutchings Subject: [PATCH 4.13 42/44] Input: ims-psu - check if CDC union descriptor is sane Date: Thu, 16 Nov 2017 18:43:06 +0100 Message-Id: <20171116172825.444275249@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171116172823.336649076@linuxfoundation.org> References: <20171116172823.336649076@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Torokhov commit ea04efee7635c9120d015dcdeeeb6988130cb67a upstream. Before trying to use CDC union descriptor, try to validate whether that it is sane by checking that intf->altsetting->extra is big enough and that descriptor bLength is not too big and not too small. Reported-by: Andrey Konovalov Signed-off-by: Dmitry Torokhov Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/input/misc/ims-pcu.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) --- a/drivers/input/misc/ims-pcu.c +++ b/drivers/input/misc/ims-pcu.c @@ -1635,13 +1635,25 @@ ims_pcu_get_cdc_union_desc(struct usb_in return NULL; } - while (buflen > 0) { + while (buflen >= sizeof(*union_desc)) { union_desc = (struct usb_cdc_union_desc *)buf; + if (union_desc->bLength > buflen) { + dev_err(&intf->dev, "Too large descriptor\n"); + return NULL; + } + if (union_desc->bDescriptorType == USB_DT_CS_INTERFACE && union_desc->bDescriptorSubType == USB_CDC_UNION_TYPE) { dev_dbg(&intf->dev, "Found union header\n"); - return union_desc; + + if (union_desc->bLength >= sizeof(*union_desc)) + return union_desc; + + dev_err(&intf->dev, + "Union descriptor to short (%d vs %zd\n)", + union_desc->bLength, sizeof(*union_desc)); + return NULL; } buflen -= union_desc->bLength;