Re: [PATCH] net: phy: Fix potential null pointer access

[Lukas Funke]

Hi Russel,

On 20.11.2023 10:51, Russell King (Oracle) wrote:
> On Mon, Nov 20, 2023 at 10:32:54AM +0100, Lukas Funke wrote:
> > From: Lukas Funke <lukas.funke@xxxxxxxxxxxxxxx>
> >
> > When there is no driver associated with the phydev, there will be a
> > nullptr access. The commit checks if the phydev driver is set before
> > access.
>
> What's the call path that we encounter a NULL drv pointer?


The patch is a bit older and the path is reconstructed from my memory:

macb_phylink_connect -> phylink_of_phy_connect -> of_phy_connect -> 
phy_connect_direct -> phy_request_interrupt

It happend when we used the Xilinx gmii2rgmii phy driver. We did a 
missconfiguration in the dt and bumped into the nullpointer exception. 
Since other functions like phy_aneg_done() also check for driver 
existence I thought it would be a good addition.

> Thanks.