From mboxrd@z Thu Jan  1 00:00:00 1970
From: Florian Westphal <fw@strlen.de>
Subject: Re: [PATCH nf] netfilter: nf_tables: report error if stateful obj's
 name is truncated
Date: Thu, 19 Jan 2017 16:22:40 +0100
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Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
        Liping Zhang <zlpnobody@163.com>,
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To: Liping Zhang <zlpnobody@gmail.com>
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Liping Zhang <zlpnobody@gmail.com> wrote:
> > At quick glance, I can see other spots lacking this validation:
> >
> > static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] =
> > {
> >         [NFTA_CHAIN_TABLE]      = { .type = NLA_STRING },
> >
> > Probably review and fix them in one go?
> 
> The nft table name's size is limited at this place:
> static const struct nla_policy nft_table_policy[NFTA_TABLE_MAX + 1] = {
>         [NFTA_TABLE_NAME] = { .type = NLA_STRING,
>                                                    .len =
> NFT_TABLE_MAXNAMELEN - 1 },
> 
> If NFTA_CHAIN_TABLE's size exceeded 31, nf_tables_table_lookup will
> fail eventually.
> 
> So I think adding the validation of NFTA_CHAIN_TABLE's size is not
> important.

Perhaps but its better to have it anyway so that you don't need this
extra context to understand that its limited in practice.