@@ -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);
ipsec->xs->xso.real_dev = real_dev;
+ 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);
ipsec->xs->xso.real_dev = NULL;
- 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);
}
/**
@@ -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.
*/
struct net_device *real_dev;
unsigned long offload_handle;
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. 1. 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. 2. 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(). 3. 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(-)