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Date:   Tue, 1 Feb 2022 15:14:43 +0100
From:   Florian Westphal <fw@strlen.de>
To:     Pham Thanh Tuyen <phamtyn@gmail.com>
Cc:     Florian Westphal <fw@strlen.de>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
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Subject: Re: PROBLEM: Injected conntrack lost helper
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Pham Thanh Tuyen <phamtyn@gmail.com> wrote:
> Previously I also thought ct->status |= IPS_HELPER; is ok, but after
> internal pointer assigning with RCU_INIT_POINTER() need external pointer
> assigning with rcu_assign_pointer() in __nf_ct_try_assign_helper() function.

I'm not following.

__nf_ct_try_assign_helper() doesn't do anything once that flag is set,
so how could the helper get lost later?