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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C46BAC3A5A1 for ; Thu, 22 Aug 2019 17:09:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95E9623431 for ; Thu, 22 Aug 2019 17:09:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566493751; bh=dmpAG+jXk1w4jDYTvVqCkRzkHJ94KtVhPWJc1JIVRwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R0XsAIFP6owZj6Js3Nrnal0BZ5DpW1qgcS1o+3jbHFPscTJPephdQ1qvrxoTaoODq 6spocxHHpfilJZYnt0I0uPVXLXHK6M+bfyvJ+sLpXmcZJyuKu0PlXCRHsFQrhmQpnR z1xSDfR4MhGTLDUTos4IgG48GcwJc+u0uZgsMKmI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390690AbfHVRJK (ORCPT ); Thu, 22 Aug 2019 13:09:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:59282 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390652AbfHVRJF (ORCPT ); Thu, 22 Aug 2019 13:09:05 -0400 Received: from sasha-vm.mshome.net (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ABA6123427; Thu, 22 Aug 2019 17:09:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566493744; bh=dmpAG+jXk1w4jDYTvVqCkRzkHJ94KtVhPWJc1JIVRwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OZDN8NLVnWgPBSKRMs0yQWr3TSAKXCB/BruXsrQgeBEhit5QP3rr8Nl+gFub+DmQa tqFiN+CAvdN8Obe9CgDTDU/G0XZ1n9gnbc9iTKujIDBsytR1Ke1uENwKYjj6clAwwF ZTxeZdQCxdvpZDHOBagw/62xdhqrBEg7nhfsRqNI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ian Abbott , David Binderman , Greg Kroah-Hartman Subject: [PATCH 5.2 092/135] staging: comedi: dt3000: Fix signed integer overflow 'divider * base' Date: Thu, 22 Aug 2019 13:07:28 -0400 Message-Id: <20190822170811.13303-93-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190822170811.13303-1-sashal@kernel.org> References: <20190822170811.13303-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.2.10-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.2.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.2.10-rc1 X-KernelTest-Deadline: 2019-08-24T17:07+00:00 X-stable: review X-Patchwork-Hint: Ignore 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 b4d98bc3fc93ec3a58459948a2c0e0c9b501cd88 upstream. In `dt3k_ns_to_timer()` the following lines near the end of the function result in a signed integer overflow: prescale = 15; base = timer_base * (1 << prescale); divider = 65535; *nanosec = divider * base; (`divider`, `base` and `prescale` are type `int`, `timer_base` and `*nanosec` are type `unsigned int`. The value of `timer_base` will be either 50 or 100.) The main reason for the overflow is that the calculation for `base` is completely wrong. It should be: base = timer_base * (prescale + 1); which matches an earlier instance of this calculation in the same function. Reported-by: David Binderman Cc: Signed-off-by: Ian Abbott Link: https://lore.kernel.org/r/20190812111517.26803-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/dt3000.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/dt3000.c b/drivers/staging/comedi/drivers/dt3000.c index 2edf3ee913000..4ad176fc14ad1 100644 --- a/drivers/staging/comedi/drivers/dt3000.c +++ b/drivers/staging/comedi/drivers/dt3000.c @@ -368,7 +368,7 @@ static int dt3k_ns_to_timer(unsigned int timer_base, unsigned int *nanosec, } prescale = 15; - base = timer_base * (1 << prescale); + base = timer_base * (prescale + 1); divider = 65535; *nanosec = divider * base; return (prescale << 16) | (divider); -- 2.20.1