This is a note to let you know that I've just added the patch titled
net/mlx5e: Properly deal with encap flows add/del under neigh update
to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: net-mlx5e-properly-deal-with-encap-flows-add-del-under-neigh-update.patch and it can be found in the queue-4.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Wed Nov 15 17:25:34 CET 2017
From: Or Gerlitz ogerlitz@mellanox.com Date: Tue, 17 Oct 2017 12:33:43 +0200 Subject: net/mlx5e: Properly deal with encap flows add/del under neigh update
From: Or Gerlitz ogerlitz@mellanox.com
[ Upstream commit 3c37745ec614ff048d5dce38f976804b05d307ee ]
Currently, the encap action offload is handled in the actions parse function and not in mlx5e_tc_add_fdb_flow() where we deal with all the other aspects of offloading actions (vlan, modify header) and the rule itself.
When the neigh update code (mlx5e_tc_encap_flows_add()) recreates the encap entry and offloads the related flows, we wrongly call again into mlx5e_tc_add_fdb_flow(), this for itself would cause us to handle again the offloading of vlans and header re-write which puts things in non consistent state and step on freed memory (e.g the modify header parse buffer which is already freed).
Since on error, mlx5e_tc_add_fdb_flow() detaches and may release the encap entry, it causes a corruption at the neigh update code which goes over the list of flows associated with this encap entry, or double free when the tc flow is later deleted by user-space.
When neigh update (mlx5e_tc_encap_flows_del()) unoffloads the flows related to an encap entry which is now invalid, we do a partial repeat of the eswitch flow removal code which is wrong too.
To fix things up we do the following:
(1) handle the encap action offload in the eswitch flow add function mlx5e_tc_add_fdb_flow() as done for the other actions and the rule itself.
(2) modify the neigh update code (mlx5e_tc_encap_flows_add/del) to only deal with the encap entry and rules delete/add and not with any of the other offloaded actions.
Fixes: 232c001398ae ('net/mlx5e: Add support to neighbour update flow') Signed-off-by: Or Gerlitz ogerlitz@mellanox.com Reviewed-by: Paul Blakey paulb@mellanox.com Signed-off-by: Saeed Mahameed saeedm@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 89 ++++++++++++++---------- 1 file changed, 54 insertions(+), 35 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -78,9 +78,11 @@ struct mlx5e_tc_flow { };
struct mlx5e_tc_flow_parse_attr { + struct ip_tunnel_info tun_info; struct mlx5_flow_spec spec; int num_mod_hdr_actions; void *mod_hdr_actions; + int mirred_ifindex; };
enum { @@ -322,6 +324,12 @@ static void mlx5e_tc_del_nic_flow(struct static void mlx5e_detach_encap(struct mlx5e_priv *priv, struct mlx5e_tc_flow *flow);
+static int mlx5e_attach_encap(struct mlx5e_priv *priv, + struct ip_tunnel_info *tun_info, + struct net_device *mirred_dev, + struct net_device **encap_dev, + struct mlx5e_tc_flow *flow); + static struct mlx5_flow_handle * mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, struct mlx5e_tc_flow_parse_attr *parse_attr, @@ -329,9 +337,27 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv { struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; struct mlx5_esw_flow_attr *attr = flow->esw_attr; - struct mlx5_flow_handle *rule; + struct net_device *out_dev, *encap_dev = NULL; + struct mlx5_flow_handle *rule = NULL; + struct mlx5e_rep_priv *rpriv; + struct mlx5e_priv *out_priv; int err;
+ if (attr->action & MLX5_FLOW_CONTEXT_ACTION_ENCAP) { + out_dev = __dev_get_by_index(dev_net(priv->netdev), + attr->parse_attr->mirred_ifindex); + err = mlx5e_attach_encap(priv, &parse_attr->tun_info, + out_dev, &encap_dev, flow); + if (err) { + rule = ERR_PTR(err); + if (err != -EAGAIN) + goto err_attach_encap; + } + out_priv = netdev_priv(encap_dev); + rpriv = out_priv->ppriv; + attr->out_rep = rpriv->rep; + } + err = mlx5_eswitch_add_vlan_action(esw, attr); if (err) { rule = ERR_PTR(err); @@ -347,10 +373,14 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv } }
- rule = mlx5_eswitch_add_offloaded_rule(esw, &parse_attr->spec, attr); - if (IS_ERR(rule)) - goto err_add_rule; - + /* we get here if (1) there's no error (rule being null) or when + * (2) there's an encap action and we're on -EAGAIN (no valid neigh) + */ + if (rule != ERR_PTR(-EAGAIN)) { + rule = mlx5_eswitch_add_offloaded_rule(esw, &parse_attr->spec, attr); + if (IS_ERR(rule)) + goto err_add_rule; + } return rule;
err_add_rule: @@ -361,6 +391,7 @@ err_mod_hdr: err_add_vlan: if (attr->action & MLX5_FLOW_CONTEXT_ACTION_ENCAP) mlx5e_detach_encap(priv, flow); +err_attach_encap: return rule; }
@@ -389,6 +420,8 @@ static void mlx5e_tc_del_fdb_flow(struct void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, struct mlx5e_encap_entry *e) { + struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; + struct mlx5_esw_flow_attr *esw_attr; struct mlx5e_tc_flow *flow; int err;
@@ -404,10 +437,9 @@ void mlx5e_tc_encap_flows_add(struct mlx mlx5e_rep_queue_neigh_stats_work(priv);
list_for_each_entry(flow, &e->flows, encap) { - flow->esw_attr->encap_id = e->encap_id; - flow->rule = mlx5e_tc_add_fdb_flow(priv, - flow->esw_attr->parse_attr, - flow); + esw_attr = flow->esw_attr; + esw_attr->encap_id = e->encap_id; + flow->rule = mlx5_eswitch_add_offloaded_rule(esw, &esw_attr->parse_attr->spec, esw_attr); if (IS_ERR(flow->rule)) { err = PTR_ERR(flow->rule); mlx5_core_warn(priv->mdev, "Failed to update cached encapsulation flow, %d\n", @@ -421,15 +453,13 @@ void mlx5e_tc_encap_flows_add(struct mlx void mlx5e_tc_encap_flows_del(struct mlx5e_priv *priv, struct mlx5e_encap_entry *e) { + struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; struct mlx5e_tc_flow *flow; - struct mlx5_fc *counter;
list_for_each_entry(flow, &e->flows, encap) { if (flow->flags & MLX5E_TC_FLOW_OFFLOADED) { flow->flags &= ~MLX5E_TC_FLOW_OFFLOADED; - counter = mlx5_flow_rule_counter(flow->rule); - mlx5_del_flow_rules(flow->rule); - mlx5_fc_destroy(priv->mdev, counter); + mlx5_eswitch_del_offloaded_rule(esw, flow->rule, flow->esw_attr); } }
@@ -1871,7 +1901,7 @@ static int parse_tc_fdb_actions(struct m
if (is_tcf_mirred_egress_redirect(a)) { int ifindex = tcf_mirred_ifindex(a); - struct net_device *out_dev, *encap_dev = NULL; + struct net_device *out_dev; struct mlx5e_priv *out_priv;
out_dev = __dev_get_by_index(dev_net(priv->netdev), ifindex); @@ -1884,17 +1914,13 @@ static int parse_tc_fdb_actions(struct m rpriv = out_priv->ppriv; attr->out_rep = rpriv->rep; } else if (encap) { - err = mlx5e_attach_encap(priv, info, - out_dev, &encap_dev, flow); - if (err && err != -EAGAIN) - return err; + parse_attr->mirred_ifindex = ifindex; + parse_attr->tun_info = *info; + attr->parse_attr = parse_attr; attr->action |= MLX5_FLOW_CONTEXT_ACTION_ENCAP | MLX5_FLOW_CONTEXT_ACTION_FWD_DEST | MLX5_FLOW_CONTEXT_ACTION_COUNT; - out_priv = netdev_priv(encap_dev); - rpriv = out_priv->ppriv; - attr->out_rep = rpriv->rep; - attr->parse_attr = parse_attr; + /* attr->out_rep is resolved when we handle encap */ } else { pr_err("devices %s %s not on same switch HW, can't offload forwarding\n", priv->netdev->name, out_dev->name); @@ -1972,7 +1998,7 @@ int mlx5e_configure_flower(struct mlx5e_ if (flow->flags & MLX5E_TC_FLOW_ESWITCH) { err = parse_tc_fdb_actions(priv, f->exts, parse_attr, flow); if (err < 0) - goto err_handle_encap_flow; + goto err_free; flow->rule = mlx5e_tc_add_fdb_flow(priv, parse_attr, flow); } else { err = parse_tc_nic_actions(priv, f->exts, parse_attr, flow); @@ -1983,10 +2009,13 @@ int mlx5e_configure_flower(struct mlx5e_
if (IS_ERR(flow->rule)) { err = PTR_ERR(flow->rule); - goto err_free; + if (err != -EAGAIN) + goto err_free; }
- flow->flags |= MLX5E_TC_FLOW_OFFLOADED; + if (err != -EAGAIN) + flow->flags |= MLX5E_TC_FLOW_OFFLOADED; + err = rhashtable_insert_fast(&tc->ht, &flow->node, tc->ht_params); if (err) @@ -2000,16 +2029,6 @@ int mlx5e_configure_flower(struct mlx5e_ err_del_rule: mlx5e_tc_del_flow(priv, flow);
-err_handle_encap_flow: - if (err == -EAGAIN) { - err = rhashtable_insert_fast(&tc->ht, &flow->node, - tc->ht_params); - if (err) - mlx5e_tc_del_flow(priv, flow); - else - return 0; - } - err_free: kvfree(parse_attr); kfree(flow);
Patches currently in stable-queue which might be from ogerlitz@mellanox.com are
queue-4.13/net-mlx5e-properly-deal-with-encap-flows-add-del-under-neigh-update.patch