[PATCH 5.4 121/434] team: call RCU read lock when walking the port_list

Greg Kroah-Hartman
2019-12-29T18:09:13Z

From: Hangbin Liu <liuhangbin@gmail.com>

[ 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 <pabeni@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 8156b33ee3e7..ca70a1d840eb 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