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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 96413C433DF for ; Mon, 27 Jul 2020 14:41:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70A0820719 for ; Mon, 27 Jul 2020 14:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595860881; bh=9tz4CidWw9o+Gpp59fBPlYhlBDzhpP4SJWGqTHQVUNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=miQ31tlvmdwBVCpi1iPMzZKZt2w+EsU7xWWvq9cevMiFm8CpGAj8DYUjpakLMG9vv ZR+wY8GrCa7eZmO2o73XpVCBn9BVekwbmGsnEdfz/6JN9lHKQkJ9x9oFWD/jgEhk6G 2eyJsKX3MNvQphhGfD62VLQfZiUbP996i3I0pUIo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733057AbgG0OlT (ORCPT ); Mon, 27 Jul 2020 10:41:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:57674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729383AbgG0OIT (ORCPT ); Mon, 27 Jul 2020 10:08:19 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 68F732073E; Mon, 27 Jul 2020 14:08:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595858898; bh=9tz4CidWw9o+Gpp59fBPlYhlBDzhpP4SJWGqTHQVUNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ljIRkimzwk67YG3CyIMmP8juzqB5Jayr4c2dJiQ3C1U9MRQl9INcpxGgeFx4LK/e5 NO6iUVQspgDg4F4pne/sMKfzYgzDqvARTQtEsKEY3WlINVO83PAHbadOJ900hbwcTG +Zxl6MmPrfPslOZE3v3YVI8sAGoRa7nHzHtMMb5o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ian Abbott Subject: [PATCH 4.14 53/64] staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift Date: Mon, 27 Jul 2020 16:04:32 +0200 Message-Id: <20200727134913.795271919@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200727134911.020675249@linuxfoundation.org> References: <20200727134911.020675249@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Abbott commit fc846e9db67c7e808d77bf9e2ef3d49e3820ce5d upstream. The `INSN_CONFIG` comedi instruction with sub-instruction code `INSN_CONFIG_DIGITAL_TRIG` includes a base channel in `data[3]`. This is used as a right shift amount for other bitmask values without being checked. Shift amounts greater than or equal to 32 will result in undefined behavior. Add code to deal with this, adjusting the checks for invalid channels so that enabled channel bits that would have been lost by shifting are also checked for validity. Only channels 0 to 15 are valid. Fixes: a8c66b684efaf ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions") Cc: #4.0+: ef75e14a6c93: staging: comedi: verify array index is correct before using it Cc: #4.0+ Signed-off-by: Ian Abbott Link: https://lore.kernel.org/r/20200717145257.112660-5-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/addi_apci_1500.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) --- a/drivers/staging/comedi/drivers/addi_apci_1500.c +++ b/drivers/staging/comedi/drivers/addi_apci_1500.c @@ -461,13 +461,14 @@ static int apci1500_di_cfg_trig(struct c struct apci1500_private *devpriv = dev->private; unsigned int trig = data[1]; unsigned int shift = data[3]; - unsigned int hi_mask = data[4] << shift; - unsigned int lo_mask = data[5] << shift; - unsigned int chan_mask = hi_mask | lo_mask; - unsigned int old_mask = (1 << shift) - 1; + unsigned int hi_mask; + unsigned int lo_mask; + unsigned int chan_mask; + unsigned int old_mask; unsigned int pm; unsigned int pt; unsigned int pp; + unsigned int invalid_chan; if (trig > 1) { dev_dbg(dev->class_dev, @@ -475,7 +476,20 @@ static int apci1500_di_cfg_trig(struct c return -EINVAL; } - if (chan_mask > 0xffff) { + if (shift <= 16) { + hi_mask = data[4] << shift; + lo_mask = data[5] << shift; + old_mask = (1U << shift) - 1; + invalid_chan = (data[4] | data[5]) >> (16 - shift); + } else { + hi_mask = 0; + lo_mask = 0; + old_mask = 0xffff; + invalid_chan = data[4] | data[5]; + } + chan_mask = hi_mask | lo_mask; + + if (invalid_chan) { dev_dbg(dev->class_dev, "invalid digital trigger channel\n"); return -EINVAL; }