Re: [PATCH] net: fujitsu: fix a potential NULL pointer dereference

[David Miller]

From: Kangjie Lu <kjlu@xxxxxxx>
Date: Mon, 11 Mar 2019 01:15:01 -0500

> In case ioremap fails, the fix returns -ENOMEM to avoid the
> NULL pointer dereference.
> 
> Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
> ---
>  drivers/net/ethernet/fujitsu/fmvj18x_cs.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/fujitsu/fmvj18x_cs.c b/drivers/net/ethernet/fujitsu/fmvj18x_cs.c
> index a69cd19a55ae..5061ddf699a7 100644
> --- a/drivers/net/ethernet/fujitsu/fmvj18x_cs.c
> +++ b/drivers/net/ethernet/fujitsu/fmvj18x_cs.c
> @@ -547,6 +547,9 @@ static int fmvj18x_get_hwinfo(struct pcmcia_device *link, u_char *node_id)
>  	return -1;
>  
>      base = ioremap(link->resource[2]->start, resource_size(link->resource[2]));
> +    if (!base)
> +	    return -ENOMEM;
> +

You must release the pcmcia window if you exit the function here.