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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 2A8E3C433FF for ; Wed, 31 Jul 2019 22:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F40F9206A2 for ; Wed, 31 Jul 2019 22:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730409AbfGaW5I (ORCPT ); Wed, 31 Jul 2019 18:57:08 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:45114 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726118AbfGaW5I (ORCPT ); Wed, 31 Jul 2019 18:57:08 -0400 Received: from localhost (c-24-20-22-31.hsd1.or.comcast.net [24.20.22.31]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 6017F1264EC7E; Wed, 31 Jul 2019 15:57:07 -0700 (PDT) Date: Wed, 31 Jul 2019 18:57:05 -0400 (EDT) Message-Id: <20190731.185705.323737673654483593.davem@davemloft.net> To: baijiaju1990@gmail.com Cc: andrew@lunn.ch, f.fainelli@gmail.com, hkallweit1@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] net: phy: phy_led_triggers: Fix a possible null-pointer dereference in phy_led_trigger_change_speed() From: David Miller In-Reply-To: <20190730080813.15363-1-baijiaju1990@gmail.com> References: <20190730080813.15363-1-baijiaju1990@gmail.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 31 Jul 2019 15:57:07 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jia-Ju Bai Date: Tue, 30 Jul 2019 16:08:13 +0800 > In phy_led_trigger_change_speed(), there is an if statement on line 48 > to check whether phy->last_triggered is NULL: > if (!phy->last_triggered) > > When phy->last_triggered is NULL, it is used on line 52: > led_trigger_event(&phy->last_triggered->trigger, LED_OFF); > > Thus, a possible null-pointer dereference may occur. > > To fix this bug, led_trigger_event(&phy->last_triggered->trigger, > LED_OFF) is called when phy->last_triggered is not NULL. > > This bug is found by a static analysis tool STCheck written by > the OSLAB group in Tsinghua University. > > Signed-off-by: Jia-Ju Bai Applied, thanks.