[B.A.T.M.A.N.] [PATCH 01/26] Staging: batman-adv: only modify hna-table on active module

Andrew Lunn andrew at lunn.ch
Fri May 7 21:47:06 CEST 2010

From: Linus Lüssing <linus.luessing at web.de>

If we haven't set the module to MODULE_ACTIVE state before (in general,
no interface has yet been added to batman-adv) then the hna table is not
initialised yet. If the kernel changes the mac address of the bat0
interface at this moment then an hna_local_add() called by interface_set_mac_addr()
then resulted in a null pointer derefernce. With this patch we are now
explicitly checking before if the state is MODULE_ACTIVE right now so
that we can assume having an initialised hna table.

Signed-off-by: Linus Lüssing <linus.luessing at web.de>
Signed-off-by: Marek Lindner <lindner_marek at yahoo.de>
Signed-off-by: Andrew Lunn <andrew at lunn.ch>
 drivers/staging/batman-adv/soft-interface.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/batman-adv/soft-interface.c b/drivers/staging/batman-adv/soft-interface.c
index 0e2307f..a42b21f 100644
--- a/drivers/staging/batman-adv/soft-interface.c
+++ b/drivers/staging/batman-adv/soft-interface.c
@@ -152,9 +152,13 @@ int interface_set_mac_addr(struct net_device *dev, void *p)
 	if (!is_valid_ether_addr(addr->sa_data))
-	hna_local_remove(dev->dev_addr, "mac address changed");
+	/* only modify hna-table if it has been initialised before */
+	if (atomic_read(&module_state) == MODULE_ACTIVE) {
+		hna_local_remove(dev->dev_addr, "mac address changed");
+		hna_local_add(addr->sa_data);
+	}
 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
-	hna_local_add(dev->dev_addr);
 	return 0;

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