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 <20200914013735.GC3463198@lunn.ch>
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From:   Oded Gabbay <oded.gabbay@gmail.com>
Date:   Mon, 14 Sep 2020 08:15:53 +0300
Message-ID: <CAFCwf12Ea-QVhPX1U=Hri7bbzdx5hkecgSCMgZCF--FODNgeRg@mail.gmail.com>
Subject: Re: [PATCH v2 12/14] habanalabs/gaudi: Add ethtool support using coresight
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>,
        netdev@vger.kernel.org, SW_Drivers <SW_Drivers@habana.ai>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Omer Shpigelman <oshpigelman@habana.ai>
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On Mon, Sep 14, 2020 at 4:37 AM Andrew Lunn <andrew@lunn.ch> wrote:
>
> > +static int gaudi_nic_get_module_eeprom(struct net_device *netdev,
> > +                                     struct ethtool_eeprom *ee, u8 *data)
> > +{
> > +     struct gaudi_nic_device **ptr = netdev_priv(netdev);
> > +     struct gaudi_nic_device *gaudi_nic = *ptr;
> > +     struct hl_device *hdev = gaudi_nic->hdev;
> > +
> > +     if (!ee->len)
> > +             return -EINVAL;
> > +
> > +     memset(data, 0, ee->len);
> > +     memcpy(data, hdev->asic_prop.cpucp_nic_info.qsfp_eeprom, ee->len);
> > +
>
> You memset and then memcpy the same number of bytes?
Thanks for catching this, we will fix it.

>
> You also need to validate ee->offset, and ee->len. Otherwise this is a
> vector for user space to read kernel memory after
> hdev->asic_prop.cpucp_nic_info.qsfp_eeprom. See drivers/net/phy/sfp.c:
> sfp_module_eeprom() as a good example of this validation.
>
>     Andrew

Thanks for the pointer, we will take a look and fix it.
Oded