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authorMahesh Bandewar <maheshb@google.com>2016-09-01 22:18:34 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-30 10:18:36 +0200
commitf357a79839f95f5ea7baf1c1366d64796d833bca (patch)
tree907454b9e61c748186598a9af76e79510cf3f72e /net
parent56e5ad1e1d7a2ab2d79ef004a29d15e0a137a0d0 (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>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c16
1 files changed, 16 insertions, 0 deletions
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