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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 404B7C433FE for ; Fri, 21 Jan 2022 14:06:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350897AbiAUOGD (ORCPT ); Fri, 21 Jan 2022 09:06:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348573AbiAUOGC (ORCPT ); Fri, 21 Jan 2022 09:06:02 -0500 Received: from mail-oi1-x231.google.com (mail-oi1-x231.google.com [IPv6:2607:f8b0:4864:20::231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F655C061574; Fri, 21 Jan 2022 06:06:02 -0800 (PST) Received: by mail-oi1-x231.google.com with SMTP id w188so13569198oiw.13; Fri, 21 Jan 2022 06:06:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ib6uWpFzOIJS5K3QRgxaJf0K1cZH9571u93z71YZSO4=; b=Nzx15lz6LfiKl+jbHrjr7Odqpv8lX5XRt/2Ds/94/jpf+CLTRzIt2/WFJy+pWcEHPw XWcS4elk+UYrvU57UY+MOgSkSPf2WKWo3GJ3RQ+pK4smgTwSluNSvLrlM4vytQ9/P7Tr vNa5ToV77RVD3/o/+gnFf879j7jgq8Eu06aTKD8kPMNFjB44u3EnfHCBezdlKbIoyyzp Hbe2AZe+YaDAfLQp1D0S0JhdAEs8919m4uZX6vXgPKgct1SSieqp2gRnkUXU1jX2q9k0 pLdSOVd7Tk4ytvClnS3P6siP83EYgzzWkdDZKWiM0QCFdpM2auDU5a7XAsdj+bpM2Mij edzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=ib6uWpFzOIJS5K3QRgxaJf0K1cZH9571u93z71YZSO4=; b=GWM1mr7h7D82KxKZD0vO1WYXXbauHoAUz/HytqBirNDHf2aEpdYqp1vz0oBpQrOiAZ kZws69ItWx8c7h2vlvKxv/FFXeX3Xwvs5vtssAc3Jq9dVnphEdmaohjs5mPAy5EFgMN4 dHd/OBpkMLBdDjTy3x1GqO45ILe2ZXzyGXJYp9j+SJWVrEGqwqEryimE6PVfGtGJH5s6 h21g3Jb3U+gJJU5DnByZsMCOBWasjqjq9/uKP0v63kgyG4Sp5fWDaaOZCJkl+jrnIzNH ciMEEfv8o3lZId91EqcTvYCXSOubppg/mhVK3a8k4143LdVkmt3q6YVZo5Ap/pzhiR0l 5b5g== X-Gm-Message-State: AOAM532OmbXDP30Em+xKg6pz6jGvt4aYq+7IzBjwcIyY6TV3XLyqik7c 7L2pXppMw1YlIm9b0oS0f4k= X-Google-Smtp-Source: ABdhPJy71p+WlpQw0uaWsZgf6BI0kDz4IhTdIlFuKrkqq3s4+tGUPzVwehtdrWEJMaK6RK9NPw9Y0g== X-Received: by 2002:a54:4498:: with SMTP id v24mr649458oiv.126.1642773961932; Fri, 21 Jan 2022 06:06:01 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id k17sm1074761otk.80.2022.01.21.06.06.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Jan 2022 06:06:01 -0800 (PST) Sender: Guenter Roeck Date: Fri, 21 Jan 2022 06:05:59 -0800 From: Guenter Roeck To: Dan Carpenter Cc: Jean Delvare , Chris Packham , linux-hwmon@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH v2] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write() Message-ID: <20220121140559.GA307376@roeck-us.net> References: <20220121115543.GA25292@kili> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220121115543.GA25292@kili> Precedence: bulk List-ID: X-Mailing-List: kernel-janitors@vger.kernel.org On Fri, Jan 21, 2022 at 02:55:43PM +0300, Dan Carpenter wrote: > The "val" variable is controlled by the user and comes from > hwmon_attr_store(). The FAN_RPM_TO_PERIOD() macro divides by "val" > so a zero will crash the system. Check for that and return -EINVAL. > Negatives are also invalid so return -EINVAL for those too. > > Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API") > Signed-off-by: Dan Carpenter Applied. Thanks, Guenter > --- > drivers/hwmon/adt7470.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c > index d519aca4a9d6..fb6d14d213a1 100644 > --- a/drivers/hwmon/adt7470.c > +++ b/drivers/hwmon/adt7470.c > @@ -662,6 +662,9 @@ static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val > struct adt7470_data *data = dev_get_drvdata(dev); > int err; > > + if (val <= 0) > + return -EINVAL; > + > val = FAN_RPM_TO_PERIOD(val); > val = clamp_val(val, 1, 65534); > > -- > 2.20.1 >