Re: [PATCH] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node

[David Miller]

From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Date: Wed, 15 Apr 2020 16:36:19 +0800

> nr_add_node() invokes nr_neigh_get_dev(), which returns a local
> reference of the nr_neigh object to "nr_neigh" with increased refcnt.
> 
> When nr_add_node() returns, "nr_neigh" becomes invalid, so the refcount
> should be decreased to keep refcount balanced.
> 
> The issue happens in one normal path of nr_add_node(), which forgets to
> decrease the refcnt increased by nr_neigh_get_dev() and causes a refcnt
> leak. It should decrease the refcnt before the function returns like
> other normal paths do.
> 
> Fix this issue by calling nr_neigh_put() before the nr_add_node()
> returns.
> 
> Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>

Applied and queued up for -stable, thanks.