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

[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 <yanzhen@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

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

[Florian Westphal]

Yan Zhen <yanzhen@vivo.com> wrote:
> When we are allocating an array, using kmemdup_array() to take care about
> multiplication and possible overflows.
> 
> Also it makes auditing the code easier.

Reviewed-by: Florian Westphal <fw@strlen.de>

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

[Pablo Neira Ayuso]

On Mon, Aug 26, 2024 at 11:41:36AM +0800, Yan Zhen wrote:
> When we are allocating an array, using kmemdup_array() to take care about
> multiplication and possible overflows.
> 
> Also it makes auditing the code easier.

Applied, thanks