[PATCH 2/2 v2] netfilter: nf_tables: fix oops when using gotos

[Pablo Neira Ayuso <pablo@netfilter.org>]

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@netfilter.org>
---
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);
 }
 EXPORT_SYMBOL_GPL(nft_do_chain);
 
-- 
1.7.10.4