Let the kmemdup_array() take care about multiplication and possible
overflows.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 net/ipv4/netfilter/ip_tables.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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;
-- 
2.34.1

On Wed, Aug 28, 2024 at 03:10:03PM +0800, Jinjie Ruan wrote:
> Let the kmemdup_array() take care about multiplication and possible
> overflows.

No patch for net/ipv6/netfilter/ip6_tables.c?

We have yet another code copy & paste there.

BTW, could you collapse all these patches for netfilter in one single
patch?

Thanks.

> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>  net/ipv4/netfilter/ip_tables.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 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;
> -- 
> 2.34.1
> 
>

On Wed, Aug 28, 2024 at 10:42:12AM +0200, Pablo Neira Ayuso wrote:
> On Wed, Aug 28, 2024 at 03:10:03PM +0800, Jinjie Ruan wrote:
> > Let the kmemdup_array() take care about multiplication and possible
> > overflows.
> 
> No patch for net/ipv6/netfilter/ip6_tables.c?
> 
> We have yet another code copy & paste there.
> 
> BTW, could you collapse all these patches for netfilter in one single
> patch?

BTW, someone else seems to have made the same patch:

https://patchwork.ozlabs.org/project/netfilter-devel/patch/20240826034136.1791485-1-yanzhen@vivo.com/

it is already sitting in the queue.