3.13.11-ckt19 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiri Pirko <jiri@xxxxxxxxxxx>
commit 57e595631904c827cfa1a0f7bbd7cc9a49da5745 upstream.
Currently following race is possible in team:
CPU0 CPU1
team_port_del
team_upper_dev_unlink
priv_flags &= ~IFF_TEAM_PORT
team_handle_frame
team_port_get_rcu
team_port_exists
priv_flags & IFF_TEAM_PORT == 0
return NULL (instead of port got
from rx_handler_data)
netdev_rx_handler_unregister
The thing is that the flag is removed before rx_handler is unregistered.
If team_handle_frame is called in between, team_port_exists returns 0
and team_port_get_rcu will return NULL.
So do not check the flag here. It is guaranteed by netdev_rx_handler_unregister
that team_handle_frame will always see valid rx_handler_data pointer.
Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxxx>
Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/net/team/team.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index b4a69a7..6d357b4 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -42,9 +42,7 @@
static struct team_port *team_port_get_rcu(const struct net_device *dev)
{
- struct team_port *port = rcu_dereference(dev->rx_handler_data);
-
- return team_port_exists(dev) ? port : NULL;
+ return rcu_dereference(dev->rx_handler_data);
}
static struct team_port *team_port_get_rtnl(const struct net_device *dev)
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html