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	id 1rrvZ2-0005Wq-F3; Wed, 03 Apr 2024 10:01:44 +0200
Date: Wed, 3 Apr 2024 10:01:44 +0200
From: Florian Westphal <fw@strlen.de>
To: Ziyang Xuan <william.xuanziyang@huawei.com>
Cc: pablo@netfilter.org, kadlec@netfilter.org, fw@strlen.de,
	netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nft v2] netfilter: nf_tables: Fix pertential data-race in
 __nft_flowtable_type_get()
Message-ID: <20240403080144.GC26310@breakpoint.cc>
References: <20240403072204.2139712-1-william.xuanziyang@huawei.com>
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User-Agent: Mutt/1.10.1 (2018-07-13)

Ziyang Xuan <william.xuanziyang@huawei.com> wrote:
> nft_unregister_flowtable_type() within nf_flow_inet_module_exit() can
> concurrent with __nft_flowtable_type_get() within nf_tables_newflowtable().
> And thhere is not any protection when iterate over nf_tables_flowtables
> list in __nft_flowtable_type_get(). Therefore, there is pertential
> data-race of nf_tables_flowtables list entry.
> 
> Use list_for_each_entry_rcu() to iterate over nf_tables_flowtables list
> in __nft_flowtable_type_get(), and use rcu_read_lock() in the caller
> nft_flowtable_type_get() to protect the entire type query process.

Reviewed-by: Florian Westphal <fw@strlen.de>

Would you be so kind to send followup patches for the other two types
Pablo pointed out?

static LIST_HEAD(nf_tables_expressions);
static LIST_HEAD(nf_tables_objects);

It looks like they have same issue.

Thanks!