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Date: Wed, 20 May 2020 08:50:54 -0700
From: Stephen Hemminger <stephen@networkplumber.org>
Message-ID: <20200520085054.2031ad8a@hermes.lan>
In-Reply-To: <20181116165001.30896-1-nikolay@cumulusnetworks.com>
References: <20181114172703.5795-1-nikolay@cumulusnetworks.com>
 <20181116165001.30896-1-nikolay@cumulusnetworks.com>
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Subject: Re: [Bridge] [PATCH net v3] net: bridge: fix vlan stats
 use-after-free on destruction
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To: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Cc: netdev@vger.kernel.org, roopa@cumulusnetworks.com, bridge@lists.linux-foundation.org, syzkaller-bugs@googlegroups.com, davem@davemloft.net

On Fri, 16 Nov 2018 18:50:01 +0200
Nikolay Aleksandrov <nikolay@cumulusnetworks.com> wrote:

> +	if (v->priv_flags & BR_VLFLAG_PER_PORT_STATS)
>  		free_percpu(v->stats);

Why not not v->stats == NULL as a flag instead?

Then the fact that free_percpu(NULL) is a Nop would mean less code
in the bridge driver.