genetlink: Fix a memory leak on error path

From: YueHaibing <yuehaibing@huawei.com>

In genl_register_family(), when idr_alloc() fails,
we forget to free the memory we possibly allocate for
family->attrbuf.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 2ae0f17df1cd ("genetlink: use idr to track families")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
 net/netlink/genetlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

On 21.03.2019 10:02, Yue Haibing wrote:
> From: YueHaibing <yuehaibing@huawei.com>
> 
> In genl_register_family(), when idr_alloc() fails,
> we forget to free the memory we possibly allocate for
> family->attrbuf.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: 2ae0f17df1cd ("genetlink: use idr to track families")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>

Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>

> ---
>  net/netlink/genetlink.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
> index 25eeb6d..f0ec068 100644
> --- a/net/netlink/genetlink.c
> +++ b/net/netlink/genetlink.c
> @@ -366,7 +366,7 @@ int genl_register_family(struct genl_family *family)
>  			       start, end + 1, GFP_KERNEL);
>  	if (family->id < 0) {
>  		err = family->id;
> -		goto errout_locked;
> +		goto errout_free;
>  	}
>  
>  	err = genl_validate_assign_mc_groups(family);
> @@ -385,6 +385,7 @@ int genl_register_family(struct genl_family *family)
>  
>  errout_remove:
>  	idr_remove(&genl_fam_idr, family->id);
> +errout_free:
>  	kfree(family->attrbuf);
>  errout_locked:
>  	genl_unlock_all();
>

From: Yue Haibing <yuehaibing@huawei.com>
Date: Thu, 21 Mar 2019 15:02:50 +0800

> From: YueHaibing <yuehaibing@huawei.com>
> 
> In genl_register_family(), when idr_alloc() fails,
> we forget to free the memory we possibly allocate for
> family->attrbuf.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: 2ae0f17df1cd ("genetlink: use idr to track families")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>

Applied and queued up for -stable, thanks.