Re: [PATCH 5.11 13/31] net: bonding: fix error return code of bond_neigh_init()

[Jiri Kosina]

On Fri, 19 Mar 2021, Greg Kroah-Hartman wrote:

> From: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> 
> [ Upstream commit 2055a99da8a253a357bdfd359b3338ef3375a26c ]
> 
> When slave is NULL or slave_ops->ndo_neigh_setup is NULL, no error
> return code of bond_neigh_init() is assigned.
> To fix this bug, ret is assigned with -EINVAL in these cases.
> 
> Fixes: 9e99bfefdbce ("bonding: fix bond_neigh_init()")
> Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
>  drivers/net/bonding/bond_main.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 5fe5232cc3f3..fba6b6d1b430 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -3917,11 +3917,15 @@ static int bond_neigh_init(struct neighbour *n)
>  
>  	rcu_read_lock();
>  	slave = bond_first_slave_rcu(bond);
> -	if (!slave)
> +	if (!slave) {
> +		ret = -EINVAL;
>  		goto out;
> +	}
>  	slave_ops = slave->dev->netdev_ops;
> -	if (!slave_ops->ndo_neigh_setup)
> +	if (!slave_ops->ndo_neigh_setup) {
> +		ret = -EINVAL;
>  		goto out;
> +	}

This patch is completely broken and breaks bonding functionality 
altogether for me.

-- 
Jiri Kosina
SUSE Labs