From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net 1/1] net sched actions: fix refcnt leak in skbmod
Date: Fri, 11 May 2018 16:37:45 -0400 (EDT)
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From: Roman Mashak <mrv@mojatatu.com>
Date: Fri, 11 May 2018 14:35:33 -0400

> When application fails to pass flags in netlink TLV when replacing
> existing skbmod action, the kernel will leak refcnt:
> 
> $ tc actions get action skbmod index 1
> total acts 0
> 
>         action order 0: skbmod pipe set smac 00:11:22:33:44:55
>          index 1 ref 1 bind 0
> 
> For example, at this point a buggy application replaces the action with
> index 1 with new smac 00:aa:22:33:44:55, it fails because of zero flags,
> however refcnt gets bumped:
> 
> $ tc actions get actions skbmod index 1
> total acts 0
> 
>         action order 0: skbmod pipe set smac 00:11:22:33:44:55
>          index 1 ref 2 bind 0
> $
> 
> Tha patch fixes this by calling tcf_idr_release() on existing actions.
> 
> Fixes: 86da71b57383d ("net_sched: Introduce skbmod action")
> Signed-off-by: Roman Mashak <mrv@mojatatu.com>

Applied and queued up for -stable, thanks.