Re: [PATCH v2] net: 8390: fix potential NULL pointer dereferences

[David Miller]

From: Kangjie Lu <kjlu@xxxxxxx>
Date: Mon, 11 Mar 2019 00:16:51 -0500

> In case ioremap fails, the fix returns to avoid NULL pointer
> dereferences.
> 
> Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
> ---
>  drivers/net/ethernet/8390/pcnet_cs.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/net/ethernet/8390/pcnet_cs.c b/drivers/net/ethernet/8390/pcnet_cs.c
> index 61e43802b9a5..e2b69e214fad 100644
> --- a/drivers/net/ethernet/8390/pcnet_cs.c
> +++ b/drivers/net/ethernet/8390/pcnet_cs.c
> @@ -289,6 +289,9 @@ static struct hw_info *get_hwinfo(struct pcmcia_device *link)
>  
>      virt = ioremap(link->resource[2]->start,
>  	    resource_size(link->resource[2]));
> +    if (unlikely(!virt))
> +	    return NULL;
> +

You have to release the pcmcia window if you bail here.