Re: [PATCH -next] i3c: master: svc: drop free_irq of devm_request_irq allocated irq

[Miquel Raynal]

Hi Yang,

Yang Yingliang <yangyingliang@xxxxxxxxxx> wrote on Tue, 18 May 2021
21:11:27 +0800:

> irq allocated with devm_request_irq should not be freed using
> free_irq, because doing so causes a dangling pointer, and a
> subsequent double free.
> 
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
>  drivers/i3c/master/svc-i3c-master.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 1f6ba4221817..761c9c468357 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -1448,7 +1448,7 @@ static int svc_i3c_master_remove(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	free_irq(master->irq, master);
> +	devm_free_irq(&pdev->dev, master->irq, master);

Wouldn't removing this call the right solution? If it's a device
managed resource, it won't probably be needed to free it explicitly in
the remove path.

>  	clk_disable_unprepare(master->pclk);
>  	clk_disable_unprepare(master->fclk);
>  	clk_disable_unprepare(master->sclk);

Thanks,
Miquèl