diff options
author | Mahesh Bandewar <maheshb@google.com> | 2016-09-01 22:18:34 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-30 10:18:36 +0200 |
commit | f357a79839f95f5ea7baf1c1366d64796d833bca (patch) | |
tree | 907454b9e61c748186598a9af76e79510cf3f72e | |
parent | 56e5ad1e1d7a2ab2d79ef004a29d15e0a137a0d0 (diff) |
bonding: Fix bonding crash
[ Upstream commit 24b27fc4cdf9e10c5e79e5923b6b7c2c5c95096c ]
Following few steps will crash kernel -
(a) Create bonding master
> modprobe bonding miimon=50
(b) Create macvlan bridge on eth2
> ip link add link eth2 dev mvl0 address aa:0:0:0:0:01 \
type macvlan
(c) Now try adding eth2 into the bond
> echo +eth2 > /sys/class/net/bond0/bonding/slaves
<crash>
Bonding does lots of things before checking if the device enslaved is
busy or not.
In this case when the notifier call-chain sends notifications, the
bond_netdev_event() assumes that the rx_handler /rx_handler_data is
registered while the bond_enslave() hasn't progressed far enough to
register rx_handler for the new slave.
This patch adds a rx_handler check that can be performed right at the
beginning of the enslave code to avoid getting into this situation.
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/net/bonding/bond_main.c | 7 | ||||
-rw-r--r-- | include/linux/netdevice.h | 1 | ||||
-rw-r--r-- | net/core/dev.c | 16 |
3 files changed, 21 insertions, 3 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index b3d70a7a5262..5dca77e0ffed 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1317,9 +1317,10 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) slave_dev->name); } - /* already enslaved */ - if (slave_dev->flags & IFF_SLAVE) { - netdev_dbg(bond_dev, "Error: Device was already enslaved\n"); + /* already in-use? */ + if (netdev_is_rx_handler_busy(slave_dev)) { + netdev_err(bond_dev, + "Error: Device is in use and cannot be enslaved\n"); return -EBUSY; } diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index b97d6823ef3c..4e9c75226f07 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3036,6 +3036,7 @@ static inline void napi_free_frags(struct napi_struct *napi) napi->skb = NULL; } +bool netdev_is_rx_handler_busy(struct net_device *dev); int netdev_rx_handler_register(struct net_device *dev, rx_handler_func_t *rx_handler, void *rx_handler_data); diff --git a/net/core/dev.c b/net/core/dev.c index 9efbdb3ff78a..de4ed2b5a221 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3722,6 +3722,22 @@ static inline struct sk_buff *handle_ing(struct sk_buff *skb, } /** + * netdev_is_rx_handler_busy - check if receive handler is registered + * @dev: device to check + * + * Check if a receive handler is already registered for a given device. + * Return true if there one. + * + * The caller must hold the rtnl_mutex. + */ +bool netdev_is_rx_handler_busy(struct net_device *dev) +{ + ASSERT_RTNL(); + return dev && rtnl_dereference(dev->rx_handler); +} +EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy); + +/** * netdev_rx_handler_register - register receive handler * @dev: device to register a handler for * @rx_handler: receive handler to register |