From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [patch net-next] net: sched: fix use-after-free in
 tcf_block_put_ext
Date: Fri, 08 Dec 2017 14:10:31 -0500 (EST)
Message-ID: <20171208.141031.2301375886294498593.davem@davemloft.net>
References: <20171208182727.4100-1-jiri@resnulli.us>
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To: jiri@resnulli.us
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From: Jiri Pirko <jiri@resnulli.us>
Date: Fri,  8 Dec 2017 19:27:27 +0100

> From: Jiri Pirko <jiri@mellanox.com>
> 
> Since the block is freed with last chain being put, once we reach the
> end of iteration of list_for_each_entry_safe, the block may be
> already freed. I'm hitting this only by creating and deleting clsact:
 ...
> Fix this by holding the block also by chain 0 and put chain 0
> explicitly, out of the list_for_each_entry_safe loop at the very
> end of tcf_block_put_ext.
> 
> Fixes: efbf78973978 ("net_sched: get rid of rcu_barrier() in tcf_block_put_ext()")
> Signed-off-by: Jiri Pirko <jiri@mellanox.com>

Applied, thanks Jiri.