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=-19.0 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, URIBL_BLOCKED,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 5D4BCC43445 for ; Mon, 22 Mar 2021 12:59:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 355356187E for ; Mon, 22 Mar 2021 12:59:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233332AbhCVM6P (ORCPT ); Mon, 22 Mar 2021 08:58:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:40066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232377AbhCVMrb (ORCPT ); Mon, 22 Mar 2021 08:47:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4C4CC619BD; Mon, 22 Mar 2021 12:43:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1616416998; bh=mPKvOZYrPigyMhFOYXa7eMHDRkDfryfRB9QhISGllk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qAXfa1xXmVRDxx++7DSkFnQeCdmw+FfsXWKgpP0nmoA95epuHrCvhVRnXTjxAfL/Z RvT66EzKO1+dXuK6fMGBlsvh+F4JK2NragggqUp/FLoNUQO0Q4wneDBLl3ZVAApSpr xNnb7T9EiuqS3t/09sFP2r0VFGRhkGY7Wng1eS2o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fabrice Gasnier , William Breathitt Gray , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 5.4 47/60] counter: stm32-timer-cnt: fix ceiling write max value Date: Mon, 22 Mar 2021 13:28:35 +0100 Message-Id: <20210322121923.943439617@linuxfoundation.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210322121922.372583154@linuxfoundation.org> References: <20210322121922.372583154@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Fabrice Gasnier commit e4c3e133294c0a292d21073899b05ebf530169bd upstream. The ceiling value isn't checked before writing it into registers. The user could write a value higher than the counter resolution (e.g. 16 or 32 bits indicated by max_arr). This makes most significant bits to be truncated. Fix it by checking the max_arr to report a range error [1] to the user. [1] https://lkml.org/lkml/2021/2/12/358 Fixes: ad29937e206f ("counter: Add STM32 Timer quadrature encoder") Signed-off-by: Fabrice Gasnier Acked-by: William Breathitt Gray Cc: Link: https://lore.kernel.org/r/1614696235-24088-1-git-send-email-fabrice.gasnier@foss.st.com Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/counter/stm32-timer-cnt.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/counter/stm32-timer-cnt.c +++ b/drivers/counter/stm32-timer-cnt.c @@ -25,6 +25,7 @@ struct stm32_timer_cnt { struct regmap *regmap; struct clk *clk; u32 ceiling; + u32 max_arr; }; /** @@ -189,6 +190,9 @@ static ssize_t stm32_count_ceiling_write if (ret) return ret; + if (ceiling > priv->max_arr) + return -ERANGE; + /* TIMx_ARR register shouldn't be buffered (ARPE=0) */ regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0); regmap_write(priv->regmap, TIM_ARR, ceiling); @@ -366,6 +370,7 @@ static int stm32_timer_cnt_probe(struct priv->regmap = ddata->regmap; priv->clk = ddata->clk; priv->ceiling = ddata->max_arr; + priv->max_arr = ddata->max_arr; priv->counter.name = dev_name(dev); priv->counter.parent = dev;