Re: [PATCH] net: ti: icssg-prueth: Fix device_node refcount leak in prueth_probe()

[Simon Horman <horms@kernel.org>]

On Fri, Oct 30, 2026 at 04:56:51PM +0800, laixiangwu wrote:
> prueth_probe() takes references on the eth0_node/eth1_node device nodes
> with of_node_get() and stores them in prueth->eth_node[]. If either of
> the "ti,mii-g-rt" or "ti,mii-rt" syscon regmap lookups fails, probe()
> returns -ENODEV without dropping those references, leaking the device
> nodes.
> 
> Jump to the existing put_cores label so the error path releases the
> eth0_node/eth1_node references like all the other failure paths in the
> function do.
> 
> Fixes: 128d5874c082 ("net: ti: icssg-prueth: Add ICSSG ethernet driver")
> Signed-off-by: laixiangwu <laixiangwu@cmss.chinamobile.com>
> ---
>  drivers/net/ethernet/ti/icssg/icssg_prueth.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> index 591be5c80..9b971d1df 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> @@ -2258,13 +2258,15 @@ static int prueth_probe(struct platform_device *pdev)
>  	prueth->miig_rt = syscon_regmap_lookup_by_phandle(np, "ti,mii-g-rt");
>  	if (IS_ERR(prueth->miig_rt)) {
>  		dev_err(dev, "couldn't get ti,mii-g-rt syscon regmap\n");
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto put_cores;
>  	}
>  
>  	prueth->mii_rt = syscon_regmap_lookup_by_phandle(np, "ti,mii-rt");
>  	if (IS_ERR(prueth->mii_rt)) {
>  		dev_err(dev, "couldn't get ti,mii-rt syscon regmap\n");
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto put_cores;
>  	}
>  
>  	prueth->pa_stats = syscon_regmap_lookup_by_phandle(np, "ti,pa-stats");

Hi Laixianwu,

Thanks, this patch looks correct to me.
And I appreciate your feedback to the AI bots.

But I wonder if this nearby check also leaks a reference,
because while it drops one, wouldn't there be two if the
condition is met?

        if (eth0_node == eth1_node) {
                dev_err(dev, "port0 and port1 can't have same reg\n");
                of_node_put(eth0_node);
                return -ENODEV;
        }

Also, for future reference, it would probably be better to put
two similar fixes for related drivers in a two-patch patch-set,
rather than posting them separately.