[PATCH v2 nf] netfilter: log: Check param to avoid overflow in nf_log_set

From: Gao Feng <redacted>

The nf_log_set is an interface function, so it should do the strict sanity
check of parameters. Convert the return value of nf_log_set as int instead
of void. When the pf is invalid, return -EOPNOTSUPP.

Signed-off-by: Gao Feng <redacted>
---
 v2: Use ARRAY_SIZE(net->nf.nf_loggers) instead of NFPROTO_NUMPROTO;
     Return error code -EOPNOTSUPP when pf is invalid;
 v1: Initial patch

 include/net/netfilter/nf_log.h       | 2 +-
 net/bridge/netfilter/nf_log_bridge.c | 3 +--
 net/ipv4/netfilter/nf_log_arp.c      | 3 +--
 net/ipv4/netfilter/nf_log_ipv4.c     | 3 +--
 net/ipv6/netfilter/nf_log_ipv6.c     | 3 +--
 net/netfilter/nf_log.c               | 8 +++++---
 6 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h
index 83d855b..f4eebd0 100644
--- a/include/net/netfilter/nf_log.h
+++ b/include/net/netfilter/nf_log.h

@@ -60,7 +60,7 @@ struct nf_logger {
 int nf_log_register(u_int8_t pf, struct nf_logger *logger);
 void nf_log_unregister(struct nf_logger *logger);

-void nf_log_set(struct net *net, u_int8_t pf,
+int nf_log_set(struct net *net, u_int8_t pf,
                const struct nf_logger *logger);
 void nf_log_unset(struct net *net, const struct nf_logger *logger);

diff --git a/net/bridge/netfilter/nf_log_bridge.c b/net/bridge/netfilter/nf_log_bridge.c
index 5d9953a..1663df5 100644
--- a/net/bridge/netfilter/nf_log_bridge.c
+++ b/net/bridge/netfilter/nf_log_bridge.c

@@ -50,8 +50,7 @@ static struct nf_logger nf_bridge_logger __read_mostly = {

 static int __net_init nf_log_bridge_net_init(struct net *net)
 {
-       nf_log_set(net, NFPROTO_BRIDGE, &nf_bridge_logger);
-       return 0;
+       return nf_log_set(net, NFPROTO_BRIDGE, &nf_bridge_logger);
 }

 static void __net_exit nf_log_bridge_net_exit(struct net *net)

diff --git a/net/ipv4/netfilter/nf_log_arp.c b/net/ipv4/netfilter/nf_log_arp.c
index e7ad950..73599f2 100644
--- a/net/ipv4/netfilter/nf_log_arp.c
+++ b/net/ipv4/netfilter/nf_log_arp.c

@@ -111,8 +111,7 @@ static struct nf_logger nf_arp_logger __read_mostly = {

 static int __net_init nf_log_arp_net_init(struct net *net)
 {
-       nf_log_set(net, NFPROTO_ARP, &nf_arp_logger);
-       return 0;
+       return nf_log_set(net, NFPROTO_ARP, &nf_arp_logger);
 }

 static void __net_exit nf_log_arp_net_exit(struct net *net)

diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c
index 076aadd..20f2255 100644
--- a/net/ipv4/netfilter/nf_log_ipv4.c
+++ b/net/ipv4/netfilter/nf_log_ipv4.c

@@ -347,8 +347,7 @@ static struct nf_logger nf_ip_logger __read_mostly = {

 static int __net_init nf_log_ipv4_net_init(struct net *net)
 {
-       nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);
-       return 0;
+       return nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);
 }

 static void __net_exit nf_log_ipv4_net_exit(struct net *net)

diff --git a/net/ipv6/netfilter/nf_log_ipv6.c b/net/ipv6/netfilter/nf_log_ipv6.c
index 8dd8696..c1bcf69 100644
--- a/net/ipv6/netfilter/nf_log_ipv6.c
+++ b/net/ipv6/netfilter/nf_log_ipv6.c

@@ -379,8 +379,7 @@ static struct nf_logger nf_ip6_logger __read_mostly = {

 static int __net_init nf_log_ipv6_net_init(struct net *net)
 {
-       nf_log_set(net, NFPROTO_IPV6, &nf_ip6_logger);
-       return 0;
+       return nf_log_set(net, NFPROTO_IPV6, &nf_ip6_logger);
 }

 static void __net_exit nf_log_ipv6_net_exit(struct net *net)

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index aa5847a..30a17d6 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c

@@ -39,12 +39,12 @@ static struct nf_logger *__find_logger(int pf, const char *str_logger)
        return NULL;
 }

-void nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
+int nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
 {
        const struct nf_logger *log;

-       if (pf == NFPROTO_UNSPEC)
-               return;
+       if (pf == NFPROTO_UNSPEC || pf >= ARRAY_SIZE(net->nf.nf_loggers))
+               return -EOPNOTSUPP;

        mutex_lock(&nf_log_mutex);
        log = nft_log_dereference(net->nf.nf_loggers[pf]);

@@ -52,6 +52,8 @@ void nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
                rcu_assign_pointer(net->nf.nf_loggers[pf], logger);

        mutex_unlock(&nf_log_mutex);
+
+       return 0;
 }
 EXPORT_SYMBOL(nf_log_set);

--

1.9.1