From: Ido Schimmel <idosch@mellanox.com>
Date: Wed, 29 Jul 2020 09:26:45 +0000 (+0300)
Subject: mlxsw: core: Increase scope of RCU read-side critical section
X-Git-Tag: v4.14.192~19
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6e0fdf004d8539df351f3a33e45e01575352b61c;p=users%2Fdwmw2%2Flinux.git

mlxsw: core: Increase scope of RCU read-side critical section

[ Upstream commit 7d8e8f3433dc8d1dc87c1aabe73a154978fb4c4d ]

The lifetime of the Rx listener item ('rxl_item') is managed using RCU,
but is dereferenced outside of RCU read-side critical section, which can
lead to a use-after-free.

Fix this by increasing the scope of the RCU read-side critical section.

Fixes: 93c1edb27f9e ("mlxsw: Introduce Mellanox switch driver core")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 96f9f267d16d4..a2161b1409047 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -1574,11 +1574,13 @@ void mlxsw_core_skb_receive(struct mlxsw_core *mlxsw_core, struct sk_buff *skb,
 			break;
 		}
 	}
-	rcu_read_unlock();
-	if (!found)
+	if (!found) {
+		rcu_read_unlock();
 		goto drop;
+	}
 
 	rxl->func(skb, local_port, rxl_item->priv);
+	rcu_read_unlock();
 	return;
 
 drop: