[PATCH net-next v1] netfilter: Use kmemdup_array instead of kmemdup for multiple allocation

[Yan Zhen]

When we are allocating an array, using kmemdup_array() to take care about
multiplication and possible overflows.

Also it makes auditing the code easier.

Signed-off-by: Yan Zhen <yanz...@vivo.com>
---
 net/bridge/netfilter/ebtables.c | 2 +-
 net/ipv4/netfilter/arp_tables.c | 2 +-
 net/ipv4/netfilter/ip_tables.c  | 2 +-
 net/ipv6/netfilter/ip6_tables.c | 2 +-
 net/netfilter/nf_nat_core.c     | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index cbd0e3586c3f..3e67d4aff419 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1256,7 +1256,7 @@ int ebt_register_table(struct net *net, const struct 
ebt_table *input_table,
                goto free_unlock;
        }
 
-       ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+       ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
        if (!ops) {
                ret = -ENOMEM;
                if (newinfo->nentries)
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 14365b20f1c5..4493a785c1ea 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1547,7 +1547,7 @@ int arpt_register_table(struct net *net,
                goto out_free;
        }
 
-       ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+       ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
        if (!ops) {
                ret = -ENOMEM;
                goto out_free;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index fe89a056eb06..096bfef472b1 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1767,7 +1767,7 @@ int ipt_register_table(struct net *net, const struct 
xt_table *table,
                goto out_free;
        }
 
-       ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+       ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
        if (!ops) {
                ret = -ENOMEM;
                goto out_free;
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 131f7bb2110d..7d5602950ae7 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1773,7 +1773,7 @@ int ip6t_register_table(struct net *net, const struct 
xt_table *table,
                goto out_free;
        }
 
-       ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+       ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
        if (!ops) {
                ret = -ENOMEM;
                goto out_free;
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 016c816d91cb..6d8da6dddf99 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -1104,7 +1104,7 @@ int nf_nat_register_fn(struct net *net, u8 pf, const 
struct nf_hook_ops *ops,
        if (!nat_proto_net->nat_hook_ops) {
                WARN_ON(nat_proto_net->users != 0);
 
-               nat_ops = kmemdup(orig_nat_ops, sizeof(*orig_nat_ops) * 
ops_count, GFP_KERNEL);
+               nat_ops = kmemdup_array(orig_nat_ops, ops_count, 
sizeof(*orig_nat_ops), GFP_KERNEL);
                if (!nat_ops) {
                        mutex_unlock(&nf_nat_proto_mutex);
                        return -ENOMEM;
-- 
2.34.1