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Date:   Wed, 2 Nov 2022 10:47:00 +0100
From:   Pablo Neira Ayuso <pablo@netfilter.org>
To:     Chen Zhongjin <chenzhongjin@huawei.com>
Cc:     linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org,
        coreteam@netfilter.org, netdev@vger.kernel.org,
        bpf@vger.kernel.org, kadlec@netfilter.org, fw@strlen.de,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, ast@kernel.org, lorenzo@kernel.org,
        john.fastabend@gmail.com
Subject: Re: [PATCH net v2] netfilter: nf_nat: Fix possible memory leak in
 nf_nat_init()
Message-ID: <Y2I8lIldVgo7f3Tc@salvia>
References: <20221101115252.17340-1-chenzhongjin@huawei.com>
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In-Reply-To: <20221101115252.17340-1-chenzhongjin@huawei.com>
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On Tue, Nov 01, 2022 at 07:52:52PM +0800, Chen Zhongjin wrote:
> In nf_nat_init(), register_nf_nat_bpf() can fail and return directly
> without any error handling.
> Then nf_nat_bysource will leak and registering of &nat_net_ops,
> &follow_master_nat and nf_nat_hook won't be reverted.
> 
> This leaves wild ops in linkedlists and when another module tries to
> call register_pernet_operations() or nf_ct_helper_expectfn_register()
> it triggers page fault:
> 
>  BUG: unable to handle page fault for address: fffffbfff81b964c
>  RIP: 0010:register_pernet_operations+0x1b9/0x5f0
>  Call Trace:
>  <TASK>
>   register_pernet_subsys+0x29/0x40
>   ebtables_init+0x58/0x1000 [ebtables]
>   ...
> 
> Fixes: 820dc0523e05 ("net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.c")
> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
> ---
> Also revert the operation for &follow_master_nat and nf_nat_hook,
> then slightly fix commit msg for it.

Applied, thanks