[PATCH 11/15] netfilter: nf_tables: don't assume chain stats are set when jumplabel is set

[Pablo Neira Ayuso]

From: Florian Westphal <f...@strlen.de>

nft_chain_stats_replace() and all other spots assume ->stats can be
NULL, but nft_update_chain_stats does not.  It must do this check,
just because the jump label is set doesn't mean all basechains have stats
assigned.

Signed-off-by: Florian Westphal <f...@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/nf_tables_core.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index dfd0bf3810d2..942702a2776f 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -119,15 +119,22 @@ DEFINE_STATIC_KEY_FALSE(nft_counters_enabled);
 static noinline void nft_update_chain_stats(const struct nft_chain *chain,
                                            const struct nft_pktinfo *pkt)
 {
+       struct nft_base_chain *base_chain;
        struct nft_stats *stats;
 
-       local_bh_disable();
-       stats = this_cpu_ptr(rcu_dereference(nft_base_chain(chain)->stats));
-       u64_stats_update_begin(&stats->syncp);
-       stats->pkts++;
-       stats->bytes += pkt->skb->len;
-       u64_stats_update_end(&stats->syncp);
-       local_bh_enable();
+       base_chain = nft_base_chain(chain);
+       if (!base_chain->stats)
+               return;
+
+       stats = this_cpu_ptr(rcu_dereference(base_chain->stats));
+       if (stats) {
+               local_bh_disable();
+               u64_stats_update_begin(&stats->syncp);
+               stats->pkts++;
+               stats->bytes += pkt->skb->len;
+               u64_stats_update_end(&stats->syncp);
+               local_bh_enable();
+       }
 }
 
 struct nft_jumpstack {
-- 
2.11.0