Re: [PATCH 2/2] can: m_can: m_can_class_allocate_dev(): remove impossible error return judgment

[Xulin Sun]

On 2021/2/5 下午4:19, Marc Kleine-Budde wrote:
> On 05.02.2021 15:25:59, Xulin Sun wrote:
> > If the previous can_net device has been successfully allocated, its
> > private data structure is impossible to be empty, remove this redundant
> > error return judgment. Otherwise, memory leaks for alloc_candev() will
> > be triggered.
> Your analysis is correct, the netdev_priv() will never fail. But how
> will this trigger a mem leak on alloc_candev()? I've removed that

Hi Marc,

The previous code judges the netdev_priv is empty, and then goto out. 
The correct approach should add free_candev(net_dev) before goto.

The code Like:

        class_dev = netdev_priv(net_dev);
        if (!class_dev) {
                dev_err(dev, "Failed to init netdev cdevate");
+               free_candev(net_dev);
                goto out;
        }

Otherwise, memory leaks for alloc_candev() will be triggered.

Now directly remove the impossible error return judgment to resolve the above possible issue.

Thanks

Xulin

> statement. I'll add it back, if I've missed something.
>
> > Signed-off-by: Xulin Sun <xulin.sun@xxxxxxxxxxxxx>
> Applied to linux-can-next/testing.
>
> Thanks,
> Marc