Re: [PATCH net v4] net: mvpp2: fix possible invalid pointer dereference

[Hui Tang]

On 2022/11/16 12:28, Jakub Kicinski wrote:
> On Wed, 16 Nov 2022 10:14:37 +0800 Hui Tang wrote:
> > It will cause invalid pointer dereference to priv->cm3_base behind,
> > if PTR_ERR(priv->cm3_base) in mvpp2_get_sram().
> >
> > Fixes: a59d354208a7 ("net: mvpp2: enable global flow control")
> > Signed-off-by: Hui Tang <tanghui20@xxxxxxxxxx>
>
> Please do not repost new versions so often:
>
> https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#tl-dr
>
> do not use --in-reply-to

Thanks for pointing out, but should I resend it with [PATCH net v3]  or [PATCH net v5]?

> > diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> > index d98f7e9a480e..efb582b63640 100644
> > --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> > +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> > @@ -7349,6 +7349,7 @@ static int mvpp2_get_sram(struct platform_device *pdev,
> >  			  struct mvpp2 *priv)
> >  {
> >  	struct resource *res;
> > +	void __iomem *base;
> >
> >  	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
> >  	if (!res) {
> > @@ -7359,9 +7360,11 @@ static int mvpp2_get_sram(struct platform_device *pdev,
> >  		return 0;
> >  	}
> >
> > -	priv->cm3_base = devm_ioremap_resource(&pdev->dev, res);
> > +	base = devm_ioremap_resource(&pdev->dev, res);
> > +	if (!IS_ERR(base))
> > +		priv->cm3_base = base;
> >
> > -	return PTR_ERR_OR_ZERO(priv->cm3_base);
> > +	return PTR_ERR_OR_ZERO(base);
>
> Use the idiomatic error handling, keep success path un-indented:
>
> 	ptr = function();
> 	if (IS_ERR(ptr))
> 		return PTR_ERR(ptr);
>
> 	priv->bla = ptr;
> 	return 0;
> 	
Ok, I will fix it in next version