From: Vlad Buslov <vladbu@mellanox.com>
Date: Wed, 17 Jun 2020 17:51:53 +0300
Subject: net/mlx5e: Fix usage of rcu-protected pointer
Patch-mainline: v5.8-rc5
Git-commit: c1aea9e1765a047c7397da30f52315c43e3501fb
References: jsc#SLE-15172

In mlx5e_configure_flower() flow pointer is protected by rcu read lock.
However, after cited commit the pointer is being used outside of rcu read
block. Extend the block to protect all pointer accesses.

Fixes: 553f9328385d ("net/mlx5e: Support tc block sharing for representors")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -4687,13 +4687,12 @@ int mlx5e_configure_flower(struct net_de
 
 	rcu_read_lock();
 	flow = rhashtable_lookup(tc_ht, &f->cookie, tc_ht_params);
-	rcu_read_unlock();
 	if (flow) {
 		/* Same flow rule offloaded to non-uplink representor sharing tc block,
 		 * just return 0.
 		 */
 		if (is_flow_rule_duplicate_allowed(dev, rpriv) && flow->orig_dev != dev)
-			goto out;
+			goto rcu_unlock;
 
 		NL_SET_ERR_MSG_MOD(extack,
 				   "flow cookie already exists, ignoring");
@@ -4701,8 +4700,12 @@ int mlx5e_configure_flower(struct net_de
 				 "flow cookie %lx already exists, ignoring\n",
 				 f->cookie);
 		err = -EEXIST;
-		goto out;
+		goto rcu_unlock;
 	}
+rcu_unlock:
+	rcu_read_unlock();
+	if (flow)
+		goto out;
 
 	trace_mlx5e_configure_flower(f);
 	err = mlx5e_tc_add_flow(priv, f, flags, dev, &flow);