From patchwork Tue Sep 1 15:09:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 310314 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 F0E97C433E2 for ; Tue, 1 Sep 2020 16:35:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDE442065F for ; Tue, 1 Sep 2020 16:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598978125; bh=ZYFJL4b0C17ow2YomGesAH+ttcqwfDDVJAWxLjptZEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eUFZ8tPBPNdyAUlzuO2XewVC+T2EtU052zFOXijFj1eT1Q9uA3xyZ0x9lJvGT0oKo Nu0wEqd5yG468tyQPdj4BJjBOaTbhyGJrp37ZBVgoI5VDr7w8S/gOpA2DRLwCWbLTl gQWr3K+c1rczVEf1HQsBrvmJvsEDKhIMUxDWq04g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730772AbgIAQfS (ORCPT ); Tue, 1 Sep 2020 12:35:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:33250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730629AbgIAPau (ORCPT ); Tue, 1 Sep 2020 11:30:50 -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 65A842137B; Tue, 1 Sep 2020 15:30:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598974249; bh=ZYFJL4b0C17ow2YomGesAH+ttcqwfDDVJAWxLjptZEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cFMTspqO6NEXGdJVo7Q3Wt8vdXUeHGSWA7l/CzCyvNIudaXHzyHGqCen3if68t76O x7Tgj+SAeNCYWOpHvaKDpzRu0yuTh3m6EIjItaX3oVMmzCwKEaCurLOseqchCwn4MH PnuW4eVeJJfWWUl+jkFa3GsirQMXRsTQJDGPZ4iw= 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 5.4 104/214] hwmon: (nct7904) Correct divide by 0 Date: Tue, 1 Sep 2020 17:09:44 +0200 Message-Id: <20200901150957.977814932@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150952.963606936@linuxfoundation.org> References: <20200901150952.963606936@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 dfb122b5e1b76..b812b199e5e5b 100644 --- a/drivers/hwmon/nct7904.c +++ b/drivers/hwmon/nct7904.c @@ -197,7 +197,7 @@ 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; @@ -209,7 +209,7 @@ 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;