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| author | Jiri Pirko <jiri@resnulli.us> | 2015-02-23 14:02:54 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-18 13:22:27 +0100 |
| commit | 55fde24a60ef618558fef13c2413afa5daf126df (patch) | |
| tree | 83480d30eb4647614f0dd8f4e16e94657533e056 /drivers/net | |
| parent | cde81ed79fc1540a3c3e775515d72f441aef8e6c (diff) | |
| download | lwn-55fde24a60ef618558fef13c2413afa5daf126df.tar.gz lwn-55fde24a60ef618558fef13c2413afa5daf126df.zip | |
team: fix possible null pointer dereference in team_handle_frame
[ Upstream commit 57e595631904c827cfa1a0f7bbd7cc9a49da5745 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/team/team.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index 12222290c802..44d4d2a5f6c8 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) |