Re: [PATCHv4 net 1/3] bonding: move IPsec deletion to bond_ipsec_free_sa

[Hangbin Liu <liuhangbin@gmail.com>]

On Wed, Mar 05, 2025 at 04:12:18PM +0000, Cosmin Ratiu wrote:
> +++ b/drivers/net/bonding/bond_main.c
> @@ -613,8 +613,11 @@ static void bond_ipsec_del_sa_all(struct bonding
> *bond)
>  
>         mutex_lock(&bond->ipsec_lock);
>         list_for_each_entry(ipsec, &bond->ipsec_list, list) {
> -               if (!ipsec->xs->xso.real_dev)
> +               spin_lock(&ipsec->x->lock);
> +               if (!ipsec->xs->xso.real_dev) {
> +                       spin_unlock(&ipsec->x->lock);
>                         continue;
> +               }
>  
>                 if (!real_dev->xfrmdev_ops ||
>                     !real_dev->xfrmdev_ops->xdo_dev_state_delete ||
> @@ -622,12 +625,16 @@ static void bond_ipsec_del_sa_all(struct bonding
> *bond)
>                         slave_warn(bond_dev, real_dev,
>                                    "%s: no slave
> xdo_dev_state_delete\n",
>                                    __func__);
> -               } else {
> -                       real_dev->xfrmdev_ops-
> >xdo_dev_state_delete(real_dev, ipsec->xs);
> -                       if (real_dev->xfrmdev_ops->xdo_dev_state_free)
> -                               real_dev->xfrmdev_ops-
> >xdo_dev_state_free(ipsec->xs);
> -                       ipsec->xs->xso.real_dev = NULL;
> +                       spin_unlock(&ipsec->x->lock);
> +                       continue;
>                 }
> +
> +               real_dev->xfrmdev_ops->xdo_dev_state_delete(real_dev,
> ipsec->xs);
> +               ipsec->xs->xso.real_dev = NULL;
> +               /* Unlock before freeing device state, it could sleep.
> */
> +               spin_unlock(&ipsec->x->lock);
> +               if (real_dev->xfrmdev_ops->xdo_dev_state_free)
> +                       real_dev->xfrmdev_ops-
> >xdo_dev_state_free(ipsec->xs);

BTW, with setting real_dev = NULL here, I think

> To fix that, these entries should be freed here and the WARN_ON in
> bond_ipsec_free_sa() should be converted to an if...goto out, so that
> bond_ipsec_free_sa() calls would hit one of these conditions:
> 1. "if (!slave)", when no active device exists.
> 2. "if (!xs->xso.real_dev)", when xdo_dev_state_add() failed.
> 3. "if (xs->xso.real_dev != real_dev)", when a DEAD xs was already
> freed by bond_ipsec_del_sa_all() migration to a new device.
> In all 3 cases, xdo_dev_state_free() shouldn't be called, only xs
> removed from the bond->ipsec list.

The if (xs->xso.real_dev != real_dev) should never happen again.
As the real_dev = NULL, it will trigger 2 "if (!xs->xso.real_dev)"
directly.

And in bond_ipsec_add_sa_all(), it will set ipsec->xs->xso.real_dev =
real_dev, which the active slave already finished changing.

Thanks
Hangbin