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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 <davem@davemloft.net>
In-Reply-To: <20190730080813.15363-1-baijiaju1990@gmail.com>
References: <20190730080813.15363-1-baijiaju1990@gmail.com>
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From: Jia-Ju Bai <baijiaju1990@gmail.com>
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 <baijiaju1990@gmail.com>

Applied, thanks.