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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 A2AF8C433E2 for ; Tue, 1 Sep 2020 16:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FC60206A5 for ; Tue, 1 Sep 2020 16:02:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598976124; bh=rMIaUkbwsXlDXRDktehm3F7/SiCBsyj9jRFyFLhGohk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cMJYFXU8brXuNYYb/fRbd2JJXPVbiHaZ2V2hiy/OtJNm5DGePfzOqSpoLyDsVx0um Aiyim70jU7ZERgFk+5At+woS+PjTBGdZaiam9qkJMVIjwcL/j6RWImjFCHor6kc+3r 5+YEz+rp+IwVRXMGQ8f+comFpty3W6ydK8RnFf+c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731702AbgIAPnz (ORCPT ); Tue, 1 Sep 2020 11:43:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:52946 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731230AbgIAPlK (ORCPT ); Tue, 1 Sep 2020 11:41:10 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 DE092207D3; Tue, 1 Sep 2020 15:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598974869; bh=rMIaUkbwsXlDXRDktehm3F7/SiCBsyj9jRFyFLhGohk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2NDKWrmyLq7hrMqN09cdpNRj3LYkdt8pCAzLMWGfDFy9vZHTIVHogITOCZ6GRLrfF INy6BfCWpYiNSYEr9uHYP9CO+JtMOaT4T86S5BA34qe9jZV39niFZYyu43CEdZDuXh s8QZMJ2LpW2O5TYUFRq8PIOUj46lFHpTEFXqDscA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Baron , Guenter Roeck , Sasha Levin Subject: [PATCH 5.8 091/255] hwmon: (nct7904) Correct divide by 0 Date: Tue, 1 Sep 2020 17:09:07 +0200 Message-Id: <20200901151005.085204957@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901151000.800754757@linuxfoundation.org> References: <20200901151000.800754757@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: Jason Baron [ Upstream commit 8aebbbb2d573d0b4afc08b90ac7d73dba2d9da97 ] We hit a kernel panic due to a divide by 0 in nct7904_read_fan() for the hwmon_fan_min case. Extend the check to hwmon_fan_input case as well for safety. [ 1656.545650] divide error: 0000 [#1] SMP PTI [ 1656.545779] CPU: 12 PID: 18010 Comm: sensors Not tainted 5.4.47 #1 [ 1656.546065] RIP: 0010:nct7904_read+0x1e9/0x510 [nct7904] ... [ 1656.546549] RAX: 0000000000149970 RBX: ffffbd6b86bcbe08 RCX: 0000000000000000 ... [ 1656.547548] Call Trace: [ 1656.547665] hwmon_attr_show+0x32/0xd0 [hwmon] [ 1656.547783] dev_attr_show+0x18/0x50 [ 1656.547898] sysfs_kf_seq_show+0x99/0x120 [ 1656.548013] seq_read+0xd8/0x3e0 [ 1656.548127] vfs_read+0x89/0x130 [ 1656.548234] ksys_read+0x7d/0xb0 [ 1656.548342] do_syscall_64+0x48/0x110 [ 1656.548451] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: d65a5102a99f5 ("hwmon: (nct7904) Convert to use new hwmon registration API") Signed-off-by: Jason Baron Link: https://lore.kernel.org/r/1598026814-2604-1-git-send-email-jbaron@akamai.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/nct7904.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c index b0425694f7022..242ff8bee78dd 100644 --- a/drivers/hwmon/nct7904.c +++ b/drivers/hwmon/nct7904.c @@ -231,7 +231,7 @@ static int nct7904_read_fan(struct device *dev, u32 attr, int channel, if (ret < 0) return ret; cnt = ((ret & 0xff00) >> 3) | (ret & 0x1f); - if (cnt == 0x1fff) + if (cnt == 0 || cnt == 0x1fff) rpm = 0; else rpm = 1350000 / cnt; @@ -243,7 +243,7 @@ static int nct7904_read_fan(struct device *dev, u32 attr, int channel, if (ret < 0) return ret; cnt = ((ret & 0xff00) >> 3) | (ret & 0x1f); - if (cnt == 0x1fff) + if (cnt == 0 || cnt == 0x1fff) rpm = 0; else rpm = 1350000 / cnt; -- 2.25.1