Re: [PATCH net] bonding: initialize err for empty target lists

[Hangbin Liu <liuhangbin@gmail.com>]

On Thu, Aug 13, 2026 at 11:31:26PM +0800, Ruoyu Wang wrote:
> Empty NLA_NESTED attributes are valid, and bonding uses them to clear
> the ARP and NS target lists. When either target attribute is empty,
> nla_for_each_nested() does not execute, so err retains an uninitialized
> value before it is tested. The request can consequently return an
> unpredictable error after clearing the targets.
> 
> Initialize err to zero so an empty target list completes successfully.
> Non-empty lists still propagate errors from __bond_opt_set() unchanged.
> 
> This issue was found by a static analysis checker and confirmed by manual
> source review.
> 
> Fixes: 4fb0ef585eb2 ("bonding: convert arp_ip_target to use the new option API")
> Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
> ---
>  drivers/net/bonding/bond_netlink.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
> index 4a11572f663d31..87d92d3cce4a88 100644
> --- a/drivers/net/bonding/bond_netlink.c
> +++ b/drivers/net/bonding/bond_netlink.c
> @@ -220,7 +220,7 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
>  	struct bonding *bond = netdev_priv(bond_dev);
>  	struct bond_opt_value newval;
>  	int miimon = 0;
> -	int err;
> +	int err = 0;
>  
>  	if (!data)
>  		return 0;
> -- 
> 2.51.0
> 

Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn>