drivers/staging/greybus/bootrom.c: fw is NULL but dereferenced

From: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
To: linux-staging@lists.linux.dev
Cc: Viresh Kumar <vireshk@kernel.org>,
	Johan Hovold <johan@kernel.org>, Alex Elder <elder@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: drivers/staging/greybus/bootrom.c: fw is NULL but dereferenced
Date: Fri, 28 May 2021 01:39:14 +0200	[thread overview]
Message-ID: <2015099.xVv48VzNit@linux.local> (raw)

Coccinelle detected that fw is NULL but dereferenced.

static int gb_bootrom_get_firmware(struct gb_operation *op)
{
/* lines of code */
        if (!fw) {
                dev_err(dev, "%s: firmware not available\n", __func__);
                ret = -EINVAL;
                goto unlock;
        }
/* lines of code */
unlock:
        unlock:
        mutex_unlock(&bootrom->mutex);

queue_work:
        /* Refresh timeout */
        if (!ret && (offset + size == fw->size))    <--- here
	next_request = NEXT_REQ_READY_TO_BOOT;
/* lines of code */
}

I really don't know if the following change may break something else:

        if(!ret && fw && (offset + size == fw->size))
	next_request = NEXT_REQ_READY_TO_BOOT;

So, I'll leave the problem to the maintainers or to other people who know how 
the driver is supposed to manage fw == NULL.

Thanks,

Fabio