On Fri, Apr 11, 2025 at 10:49:58AM +0300, Cosmin Ratiu wrote:
Refactor the bonding ipsec offload operations to fix a number of long-standing control plane races between state migration and user deletion and a few other issues.
xfrm state deletion can happen concurrently with bond_change_active_slave() operation. This manifests itself as a bond_ipsec_del_sa() call with x->lock held, followed by a bond_ipsec_free_sa() a bit later from a wq. The alternate path of these calls coming from xfrm_dev_state_flush() can't happen, as that needs the RTNL lock and bond_change_active_slave() already holds it.
- bond_ipsec_del_sa_all() might call xdo_dev_state_delete() a second time on an xfrm state that was concurrently killed. This is bad.
- bond_ipsec_add_sa_all() can add a state on the new device, but pending bond_ipsec_free_sa() calls from the old device will then hit the WARN_ON() and then, worse, call xdo_dev_state_free() on the new device without a corresponding xdo_dev_state_delete().
- Resolve a sleeping in atomic context introduced by the mentioned "Fixes" commit.
bond_ipsec_del_sa_all() and bond_ipsec_add_sa_all() now acquire x->lock and check for x->km.state to help with problems 1 and 2. And since xso.real_dev is now a private pointer managed by the bonding driver in xfrm state, make better use of it to fully fix problems 1 and 2. In bond_ipsec_del_sa_all(), set xso.real_dev to NULL while holding both the mutex and x->lock, which makes sure that neither bond_ipsec_del_sa() nor bond_ipsec_free_sa() could run concurrently.
Fix problem 3 by moving the list cleanup (which requires the mutex) from bond_ipsec_del_sa() (called from atomic context) to bond_ipsec_free_sa()
Finally, simplify bond_ipsec_del_sa() and bond_ipsec_free_sa() by using xso->real_dev directly, since it's now protected by locks and can be trusted to always reflect the offload device.
Fixes: 2aeeef906d5a ("bonding: change ipsec_lock from spin lock to mutex") Signed-off-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Leon Romanovsky leonro@nvidia.com
drivers/net/bonding/bond_main.c | 82 +++++++++++++++------------------ include/net/xfrm.h | 7 ++- 2 files changed, 41 insertions(+), 48 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 14f7c9712ad4..8ed8c29659a0 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -545,7 +545,20 @@ static void bond_ipsec_add_sa_all(struct bonding *bond) slave_warn(bond_dev, real_dev, "%s: failed to add SA\n", __func__); continue; }
spin_lock_bh(&ipsec->xs->lock);/* xs might have been killed by the user during the migration* to the new dev, but bond_ipsec_del_sa() should have done* nothing, as xso.real_dev is NULL.* Delete it from the device we just added it to. The pending* bond_ipsec_free_sa() call will do the rest of the cleanup.*/if (ipsec->xs->km.state == XFRM_STATE_DEAD &&real_dev->xfrmdev_ops->xdo_dev_state_delete)real_dev->xfrmdev_ops->xdo_dev_state_delete(real_dev,ipsec->xs);spin_unlock_bh(&ipsec->xs->lock);out: mutex_unlock(&bond->ipsec_lock); @@ -560,48 +573,20 @@ static void bond_ipsec_del_sa(struct net_device *bond_dev, struct xfrm_state *xs) { struct net_device *real_dev;
- netdevice_tracker tracker;
- struct bond_ipsec *ipsec;
- struct bonding *bond;
- struct slave *slave;
- if (!bond_dev)
- if (!bond_dev || !xs->xso.real_dev) return;
- rcu_read_lock();
- bond = netdev_priv(bond_dev);
- slave = rcu_dereference(bond->curr_active_slave);
- real_dev = slave ? slave->dev : NULL;
- netdev_hold(real_dev, &tracker, GFP_ATOMIC);
- rcu_read_unlock();
- if (!slave)
goto out;- if (!xs->xso.real_dev)
goto out;- WARN_ON(xs->xso.real_dev != real_dev);
- real_dev = xs->xso.real_dev;
if (!real_dev->xfrmdev_ops || !real_dev->xfrmdev_ops->xdo_dev_state_delete || netif_is_bond_master(real_dev)) { slave_warn(bond_dev, real_dev, "%s: no slave xdo_dev_state_delete\n", __func__);
goto out;
return;real_dev->xfrmdev_ops->xdo_dev_state_delete(real_dev, xs); -out:
- netdev_put(real_dev, &tracker);
- mutex_lock(&bond->ipsec_lock);
- list_for_each_entry(ipsec, &bond->ipsec_list, list) {
if (ipsec->xs == xs) {list_del(&ipsec->list);kfree(ipsec);break;}- }
- mutex_unlock(&bond->ipsec_lock);
} static void bond_ipsec_del_sa_all(struct bonding *bond) @@ -629,9 +614,15 @@ static void bond_ipsec_del_sa_all(struct bonding *bond) __func__); continue; }
spin_lock_bh(&ipsec->xs->lock);
real_dev->xfrmdev_ops->xdo_dev_state_delete(real_dev,ipsec->xs);
/* Don't double delete states killed by the user. */if (ipsec->xs->km.state != XFRM_STATE_DEAD)real_dev->xfrmdev_ops->xdo_dev_state_delete(real_dev,ipsec->xs);spin_unlock_bh(&ipsec->xs->lock);- if (real_dev->xfrmdev_ops->xdo_dev_state_free) real_dev->xfrmdev_ops->xdo_dev_state_free(real_dev, ipsec->xs);
@@ -643,34 +634,33 @@ static void bond_ipsec_free_sa(struct net_device *bond_dev, struct xfrm_state *xs) { struct net_device *real_dev;
- netdevice_tracker tracker;
- struct bond_ipsec *ipsec; struct bonding *bond;
- struct slave *slave;
if (!bond_dev) return;
- rcu_read_lock(); bond = netdev_priv(bond_dev);
- slave = rcu_dereference(bond->curr_active_slave);
- real_dev = slave ? slave->dev : NULL;
- netdev_hold(real_dev, &tracker, GFP_ATOMIC);
- rcu_read_unlock();
- if (!slave)
goto out;
- mutex_lock(&bond->ipsec_lock); if (!xs->xso.real_dev) goto out;
- WARN_ON(xs->xso.real_dev != real_dev);
- real_dev = xs->xso.real_dev;
xs->xso.real_dev = NULL;
- if (real_dev && real_dev->xfrmdev_ops &&
- if (real_dev->xfrmdev_ops && real_dev->xfrmdev_ops->xdo_dev_state_free) real_dev->xfrmdev_ops->xdo_dev_state_free(real_dev, xs);
out:
- netdev_put(real_dev, &tracker);
- list_for_each_entry(ipsec, &bond->ipsec_list, list) {
if (ipsec->xs == xs) {list_del(&ipsec->list);kfree(ipsec);break;}- }
- mutex_unlock(&bond->ipsec_lock);
} /** diff --git a/include/net/xfrm.h b/include/net/xfrm.h index 3d2f6c879311..b7e8f3f49627 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -154,8 +154,11 @@ struct xfrm_dev_offload { */ struct net_device *dev; netdevice_tracker dev_tracker;
- /* This is a private pointer used by the bonding driver.
* Device drivers should not use it.
- /* This is a private pointer used by the bonding driver (and eventually
* should be moved there). Device drivers should not use it.* Protected by xfrm_state.lock AND bond.ipsec_lock in most cases,* except in the .xdo_dev_state_del() flow, where only xfrm_state.lock* is held.-- 2.45.0
Tested-by: Hangbin Liu liuhangbin@gmail.com Reviewed-by: Hangbin Liu liuhangbin@gmail.com