Re: [PATCH] irqchip: renesas-rza1: fix an use-after-free in rza1_irqc_probe()

[Marc Zyngier <maz@kernel.org>]

On Mon, 08 Jul 2019 07:19:04 +0100,
Wen Yang <wen.yang99@zte.com.cn> wrote:
> 
> The gic_node is still being used in the rza1_irqc_parse_map() call
> after the of_node_put() call, which may result in use-after-free.
> 
> Fixes: a644ccb819bc ("irqchip: Add Renesas RZ/A1 Interrupt Controller driver")
> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Chris Brandt <chris.brandt@renesas.com>
> Cc: Simon Horman <horms+renesas@verge.net.au>
> Cc: linux-kernel@vger.kernel.org
> ---
>  drivers/irqchip/irq-renesas-rza1.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-renesas-rza1.c b/drivers/irqchip/irq-renesas-rza1.c
> index b1f19b21..b0d46ac 100644
> --- a/drivers/irqchip/irq-renesas-rza1.c
> +++ b/drivers/irqchip/irq-renesas-rza1.c
> @@ -208,20 +208,19 @@ static int rza1_irqc_probe(struct platform_device *pdev)
>  		return PTR_ERR(priv->base);
>  
>  	gic_node = of_irq_find_parent(np);
> -	if (gic_node) {
> +	if (gic_node)
>  		parent = irq_find_host(gic_node);
> -		of_node_put(gic_node);
> -	}
>  
>  	if (!parent) {
>  		dev_err(dev, "cannot find parent domain\n");
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto out_put_node;
>  	}
>  
>  	ret = rza1_irqc_parse_map(priv, gic_node);
>  	if (ret) {
>  		dev_err(dev, "cannot parse %s: %d\n", "interrupt-map", ret);
> -		return ret;
> +		goto out_put_node;
>  	}
>  
>  	priv->chip.name = "rza1-irqc",
> @@ -237,10 +236,12 @@ static int rza1_irqc_probe(struct platform_device *pdev)
>  						    priv);
>  	if (!priv->irq_domain) {
>  		dev_err(dev, "cannot initialize irq domain\n");
> -		return -ENOMEM;
> +		ret = -ENOMEM;
>  	}
>  
> -	return 0;
> +out_put_node:
> +	of_node_put(gic_node);
> +	return ret;
>  }
>  
>  static int rza1_irqc_remove(struct platform_device *pdev)
> -- 
> 2.9.5
> 

Applied, thanks.

	M.

-- 
Jazz is not dead, it just smells funny.