Subject: Re: [PATCH v2] b43legacy: Add checking for null for ssb_get_devtypedata(dev)

From: Michael Büsch <[email-masked]>
Date: Tue, 18 Apr 2023 18:12:04 +0200

On Tue, 18 Apr 2023 07:29:18 -0700
Nikita Zhandarovich <[email-masked]> wrote:

> Since second call of ssb_get_devtypedata() may fail as well as the
> first one, the NULL return value in 'wl' will be later dereferenced in
> calls to b43legacy_one_core_attach() and schedule_work().

No, the second call can't fail, because b43legacy_wireless_init() will
always initialize it before returning 0.

> a/drivers/net/wireless/broadcom/b43legacy/main.c +++
> b/drivers/net/wireless/broadcom/b43legacy/main.c @@ -3857,7 +3857,11
> @@ static int b43legacy_probe(struct ssb_device *dev, if (err)
>  			goto out;
>  		wl = ssb_get_devtypedata(dev);
> -		B43legacy_WARN_ON(!wl);
> +		if (!wl) {
> +			B43legacy_WARN_ON(!wl);
> +			err = -ENODEV;
> +			goto out;

And the 'goto out' would be the wrong error recovery path, too.

> +		}
>  	}
>  	err = b43legacy_one_core_attach(dev, wl);
>  	if (err)

Nack.
Please drop this patch. The code is correct as-is.

-- 
Michael Büsch
https://bues.ch/