path: root/net/netfilter
diff options
authorLi RongQing <lirongqing@baidu.com>2019-02-26 17:13:56 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2019-03-01 14:34:24 +0100
commita9f5e78c403d2d62ade4f4c85040efc85f4049b8 (patch)
tree8f482aa30652a6cb1f3cd05806115467a7236811 /net/netfilter
parentnetfilter: bridge: Don't sabotage nf_hook calls for an l3mdev slave (diff)
netfilter: nf_tables: check the result of dereferencing base_chain->stats
Check the result of dereferencing base_chain->stats, instead of result of this_cpu_ptr with NULL. base_chain->stats maybe be changed to NULL when a chain is updated and a new NULL counter can be attached. And we do not need to check returning of this_cpu_ptr since base_chain->stats is from percpu allocator if it is non-NULL, this_cpu_ptr returns a valid value. And fix two sparse error by replacing rcu_access_pointer and rcu_dereference with READ_ONCE under rcu_read_lock. Thanks for Eric's help to finish this patch. Fixes: 009240940e84c1 ("netfilter: nf_tables: don't assume chain stats are set when jumplabel is set") Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
1 files changed, 8 insertions, 6 deletions
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index e56a94dff34e..d0f168c2670f 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -98,21 +98,23 @@ 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 __percpu *pstats;
struct nft_stats *stats;
base_chain = nft_base_chain(chain);
- if (!rcu_access_pointer(base_chain->stats))
- return;
- local_bh_disable();
- stats = this_cpu_ptr(rcu_dereference(base_chain->stats));
- if (stats) {
+ rcu_read_lock();
+ pstats = READ_ONCE(base_chain->stats);
+ if (pstats) {
+ local_bh_disable();
+ stats = this_cpu_ptr(pstats);
stats->bytes += pkt->skb->len;
+ local_bh_enable();
- local_bh_enable();
+ rcu_read_unlock();
struct nft_jumpstack {