Subject: [PATCH AUTOSEL 5.4 083/350] team: call RCU read lock when walking the port_list

From: Sasha Levin <[email-masked]>
Date: Tue, 10 Dec 2019 16:03:08 -0500

From: Hangbin Liu <[email-masked]>

[ Upstream commit c17e26ddc79596230834345be80fcad6c619e9ec ]

Before reading the team port list, we need to acquire the RCU read lock.
Also change list_for_each_entry() to list_for_each_entry_rcu().

v2:
repost the patch to net-next and remove fixes flag as this is a cosmetic
change.

Suggested-by: Paolo Abeni <[email-masked]>
Signed-off-by: Hangbin Liu <[email-masked]>
Acked-by: Paolo Abeni <[email-masked]>
Acked-by: Jiri Pirko <[email-masked]>
Signed-off-by: Jakub Kicinski <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/team/team.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 8156b33ee3e79..ca70a1d840eb3 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -2074,7 +2074,8 @@ static int team_ethtool_get_link_ksettings(struct net_device *dev,
 	cmd->base.duplex = DUPLEX_UNKNOWN;
 	cmd->base.port = PORT_OTHER;
 
-	list_for_each_entry(port, &team->port_list, list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(port, &team->port_list, list) {
 		if (team_port_txable(port)) {
 			if (port->state.speed != SPEED_UNKNOWN)
 				speed += port->state.speed;
@@ -2083,6 +2084,8 @@ static int team_ethtool_get_link_ksettings(struct net_device *dev,
 				cmd->base.duplex = port->state.duplex;
 		}
 	}
+	rcu_read_unlock();
+
 	cmd->base.speed = speed ? : SPEED_UNKNOWN;
 
 	return 0;
-- 
2.20.1