netdev - Re: [PATCH net-next] net: phy: don't crash in phy_read/_write

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Message-ID: <62029162-5a88-a015-90ad-d92bf2dc4d93@gmail.com>
Date:   Thu, 16 Jan 2020 09:52:34 -0800
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Vladimir Oltean <olteanv@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Russell King - ARM Linux admin <linux@...linux.org.uk>,
        Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>
Cc:     netdev <netdev@...r.kernel.org>,
        Alex Marginean <alexandru.marginean@....com>
Subject: Re: [PATCH net-next] net: phy: don't crash in phy_read/_write_mmd
 without a PHY driver

On 1/16/20 9:48 AM, Vladimir Oltean wrote:
> On Thu, 16 Jan 2020 at 19:46, Vladimir Oltean <olteanv@...il.com> wrote:
>>
>> From: Alex Marginean <alexandru.marginean@....com>
>>
>> The APIs can be used by Ethernet drivers without actually loading a PHY
>> driver. This may become more widespread in the future with 802.3z
>> compatible MAC PCS devices being locally driven by the MAC driver when
>> configuring for a PHY mode with in-band negotiation.
>>
>> Check that drv is not NULL before reading from it.
>>
>> Signed-off-by: Alex Marginean <alexandru.marginean@....com>
>> ---
> 
> Ugh. Can I just add here:
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>
> 
> without resending?

That's a tag that patchwork understands, so yes, that works:

http://patchwork.ozlabs.org/patch/1224348/mbox/

> 
>> If this hasn't been reported by now I assume it wasn't an issue so far.
>> So I've targeted the patch for net-next and not provided a Fixes: tag.
>>
>>  drivers/net/phy/phy-core.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
>> index 769a076514b0..a4d2d59fceca 100644
>> --- a/drivers/net/phy/phy-core.c
>> +++ b/drivers/net/phy/phy-core.c
>> @@ -387,7 +387,7 @@ int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
>>         if (regnum > (u16)~0 || devad > 32)
>>                 return -EINVAL;
>>
>> -       if (phydev->drv->read_mmd) {
>> +       if (phydev->drv && phydev->drv->read_mmd) {
>>                 val = phydev->drv->read_mmd(phydev, devad, regnum);
>>         } else if (phydev->is_c45) {
>>                 u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
>> @@ -444,7 +444,7 @@ int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
>>         if (regnum > (u16)~0 || devad > 32)
>>                 return -EINVAL;
>>
>> -       if (phydev->drv->write_mmd) {
>> +       if (phydev->drv && phydev->drv->write_mmd) {
>>                 ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
>>         } else if (phydev->is_c45) {
>>                 u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
>> --
>> 2.17.1
>>
> 
> Sorry,
> -Vladimir
> 


-- 
Florian