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authorJiri Pirko <jiri@resnulli.us>2015-02-23 14:02:54 +0100
committerDavid S. Miller <davem@davemloft.net>2015-02-23 15:30:28 -0500
commit57e595631904c827cfa1a0f7bbd7cc9a49da5745 (patch)
tree6d1164b64d8278ea97b7c87289c664d4935fd40f
parent46b9e4bb76ee26f1e024e048bb95af41b763f48f (diff)
downloadlinux-57e595631904c827cfa1a0f7bbd7cc9a49da5745.tar.bz2
team: fix possible null pointer dereference in team_handle_frame
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@resnulli.us> Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device") Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/team/team.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 0e62274e884a..f1ee71e22241 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -43,9 +43,7 @@
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)