[PATCH net] net: stmmac: dwmac-rk: Ensure clk_phy doesn't contain invalid address

[Simon Horman]

On Thu, Sep 04, 2025 at 10:54:57AM +0100, Simon Horman wrote:
> On Thu, Sep 04, 2025 at 03:12:24AM +0000, Yao Zi wrote:
> > We must set the clk_phy pointer to NULL to indicating it isn't available
> > if the optional phy clock couldn't be obtained. Otherwise the error code
> > returned by of_clk_get() could be wrongly taken as an address, causing
> > invalid pointer dereference when later clk_phy is passed to
> > clk_prepare_enable().
> > 
> > Fixes: da114122b831 ("net: ethernet: stmmac: dwmac-rk: Make the clk_phy could be used for external phy")
> > Signed-off-by: Yao Zi <ziyao at disroot.org>
> 
> ...
> 
> Hi,
> 
> I this patch doesn't seem to match upstream code.
> 
> Looking over the upstream code, it seems to me that
> going into the code in question .clk_phy should
> be NULL, as bsp_priv it is allocated using devm_kzalloc()
> over in rk_gmac_setup()
> 
> While the upstream version of the code your patch modifies
> is as follows. And doesn't touch .clk_phy if integrated_phy is not set.
> 
>         if (plat->phy_node && bsp_priv->integrated_phy) {
>                 bsp_priv->clk_phy = of_clk_get(plat->phy_node, 0);
>                 ret = PTR_ERR_OR_ZERO(bsp_priv->clk_phy);
>                 if (ret)
>                         return dev_err_probe(dev, ret, "Cannot get PHY clock\n");
>                 clk_set_rate(bsp_priv->clk_phy, 50000000);
>         }
> 
> Am I missing something?

Oops, I missed that da114122b831 is present in net-next (but not net).
Let me look over this a second time.