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Date:   Fri, 3 Apr 2020 13:03:05 -0400
Message-ID: <20200403130305.GB6453@t480s.localdomain>
From:   Vivien Didelot <vivien.didelot@gmail.com>
To:     Chuanhong Guo <gch981213@gmail.com>
Cc:     netdev@vger.kernel.org, Chuanhong Guo <gch981213@gmail.com>,
        stable@vger.kernel.org, Sean Wang <sean.wang@mediatek.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        =?UTF-8?B?UmVuw6k=?= van Dorst <opensource@vdorst.com>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: dsa: mt7530: fix null pointer dereferencing in port5
 setup
In-Reply-To: <20200403112830.505720-1-gch981213@gmail.com>
References: <20200403112830.505720-1-gch981213@gmail.com>
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On Fri,  3 Apr 2020 19:28:24 +0800, Chuanhong Guo <gch981213@gmail.com> wrote:
> The 2nd gmac of mediatek soc ethernet may not be connected to a PHY
> and a phy-handle isn't always available.
> Unfortunately, mt7530 dsa driver assumes that the 2nd gmac is always
> connected to switch port 5 and setup mt7530 according to phy address
> of 2nd gmac node, causing null pointer dereferencing when phy-handle
> isn't defined in dts.
> This commit fix this setup code by checking return value of
> of_parse_phandle before using it.
> 
> Fixes: 38f790a80560 ("net: dsa: mt7530: Add support for port 5")
> Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
> Cc: stable@vger.kernel.org

Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>