Re: [PATCH] tipc: Fix potential tipc_node refcnt leak in tipc_rcv

[David Miller]

From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Date: Wed, 15 Apr 2020 16:40:28 +0800

> tipc_rcv() invokes tipc_node_find() twice, which returns a reference of
> the specified tipc_node object to "n" with increased refcnt.
> 
> When tipc_rcv() returns or a new object is assigned to "n", the original
> local reference of "n" becomes invalid, so the refcount should be
> decreased to keep refcount balanced.
> 
> The issue happens in some paths of tipc_rcv(), which forget to decrease
> the refcnt increased by tipc_node_find() and will cause a refcnt leak.
> 
> Fix this issue by calling tipc_node_put() before the original object
> pointed by "n" becomes invalid.
> 
> Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>

Applied and queued up for -stable.