On Fri, Feb 07, 2014 at 05:29:58PM +0100, Pablo Neira Ayuso wrote:
> Fix an oops if you use the "goto" operation, you will end up in
> non-base chain with no counters and no default policy.
>
> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
> ---
> v2: recover inline to nft_chain_stats.
>
> net/netfilter/nf_tables_core.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
> index 0d879fc..13fecde 100644
> --- a/net/netfilter/nf_tables_core.c
> +++ b/net/netfilter/nf_tables_core.c
> @@ -67,18 +67,24 @@ struct nft_jumpstack {
> int rulenum;
> };
>
> -static inline void
> +static inline int
> nft_chain_stats(const struct nft_chain *this, const struct nft_pktinfo *pkt,
> struct nft_jumpstack *jumpstack, unsigned int stackptr)
> {
> struct nft_stats __percpu *stats;
> const struct nft_chain *chain = stackptr ? jumpstack[0].chain : this;
>
> + /* You can reach this through goto chain */
> + if (!(chain->flags & NFT_BASE_CHAIN))
> + return NF_ACCEPT;
> +
> rcu_read_lock_bh();
> stats = rcu_dereference(nft_base_chain(chain)->stats);
> __this_cpu_inc(stats->pkts);
> __this_cpu_add(stats->bytes, pkt->skb->len);
> rcu_read_unlock_bh();
> +
> + return nft_base_chain(chain)->policy;
> }
>
> enum nft_trace {
> @@ -209,12 +215,11 @@ next_rule:
> rulenum = jumpstack[stackptr].rulenum;
> goto next_rule;
> }
> - nft_chain_stats(chain, pkt, jumpstack, stackptr);
>
> if (unlikely(pkt->skb->nf_trace))
> nft_trace_packet(pkt, chain, ++rulenum, NFT_TRACE_POLICY);
>
> - return nft_base_chain(chain)->policy;
> + return nft_chain_stats(chain, pkt, jumpstack, stackptr);
I think we should just inline the function manually, it doesn't help
readability to have it take care of goto-specific cases and handle
verdicts/policies.
Also, what about NFT_TRACE_POLICY for the goto case? Should be generate
a message even through there is no policy?
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