[B.A.T.M.A.N.] Staging: batman-adv for 2.6.36 (7: fixes)

[B.A.T.M.A.N.] Staging: batman-adv for 2.6.36 (7: fixes)

[Sven Eckelmann]

Hi,

here are patches targeted for 2.6.36. They are smaller bugfixes and add
no new features.

I already send you 5 Patches two weeks ago which fixes problems in 2.6.36 and
one of them also in 2.6.35, but got no reply till now. So here is the reminder
you asked me before.

The patches for 2.6.37 will follow later.

thanks,
	Sven

Sven Eckelmann (3):
      Staging: batman-adv: Create batman_if only on register event
      Staging: batman-adv: Don't use net_dev after dev_put
      Staging: batman-adv: Don't write in not allocated packet_buff

 drivers/staging/batman-adv/hard-interface.c |   21 ++++++++++++---------
 1 files changed, 12 insertions(+), 9 deletions(-)

[B.A.T.M.A.N.] [PATCH 1/3] Staging: batman-adv: Create batman_if only on register event

[Sven Eckelmann]

We try to get all events for all net_devices to be able to add special
sysfs folders for the batman-adv configuration. This also includes such
events like NETDEV_POST_INIT which has no valid kobject according to
v2.6.32-rc3-13-g7ffbe3f. This would create an oops in that situation.

It is enough to create the batman_if only on NETDEV_REGISTER events
because we will also receive those events for devices which already
existed when we registered the notifier call.

Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
---
 drivers/staging/batman-adv/hard-interface.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c
index f6345c4..892166b 100644
--- a/drivers/staging/batman-adv/hard-interface.c
+++ b/drivers/staging/batman-adv/hard-interface.c
@@ -393,15 +393,13 @@ static int hard_if_event(struct notifier_block *this,
 	/* FIXME: each batman_if will be attached to a softif */
 	struct bat_priv *bat_priv = netdev_priv(soft_device);
 
-	if (!batman_if)
-		batman_if = hardif_add_interface(net_dev);
+	if (!batman_if && event == NETDEV_REGISTER)
+			batman_if = hardif_add_interface(net_dev);
 
 	if (!batman_if)
 		goto out;
 
 	switch (event) {
-	case NETDEV_REGISTER:
-		break;
 	case NETDEV_UP:
 		hardif_activate_interface(soft_device, bat_priv, batman_if);
 		break;
-- 
1.7.1

[B.A.T.M.A.N.] [PATCH 2/3] Staging: batman-adv: Don't use net_dev after dev_put

[Sven Eckelmann]

dev_put allows a device to be freed when all its references are dropped.
After that we are not allowed to access that information anymore. Access
to the data structure of a net_device must be surrounded a dev_hold
and ended using dev_put.

batman-adv adds a device to its own management structure in
hardif_add_interface and will release it in hardif_remove_interface.
Thus it must hold a reference all the time between those functions to
prevent any access to the already released net_device structure.

Reported-by: Tim Glaremin <Tim.Glaremin@web.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
---
 drivers/staging/batman-adv/hard-interface.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c
index 892166b..d08491e 100644
--- a/drivers/staging/batman-adv/hard-interface.c
+++ b/drivers/staging/batman-adv/hard-interface.c
@@ -194,8 +194,6 @@ static void hardif_activate_interface(struct net_device *net_dev,
 	if (batman_if->if_status != IF_INACTIVE)
 		return;
 
-	dev_hold(batman_if->net_dev);
-
 	update_mac_addresses(batman_if);
 	batman_if->if_status = IF_TO_BE_ACTIVATED;
 
@@ -222,8 +220,6 @@ static void hardif_deactivate_interface(struct net_device *net_dev,
 	   (batman_if->if_status != IF_TO_BE_ACTIVATED))
 		return;
 
-	dev_put(batman_if->net_dev);
-
 	batman_if->if_status = IF_INACTIVE;
 
 	bat_info(net_dev, "Interface deactivated: %s\n", batman_if->dev);
@@ -318,11 +314,13 @@ static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 	if (ret != 1)
 		goto out;
 
+	dev_hold(net_dev);
+
 	batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 	if (!batman_if) {
 		pr_err("Can't add interface (%s): out of memory\n",
 		       net_dev->name);
-		goto out;
+		goto release_dev;
 	}
 
 	batman_if->dev = kstrdup(net_dev->name, GFP_ATOMIC);
@@ -346,6 +344,8 @@ free_dev:
 	kfree(batman_if->dev);
 free_if:
 	kfree(batman_if);
+release_dev:
+	dev_put(net_dev);
 out:
 	return NULL;
 }
@@ -374,6 +374,7 @@ static void hardif_remove_interface(struct batman_if *batman_if)
 	batman_if->if_status = IF_TO_BE_REMOVED;
 	list_del_rcu(&batman_if->list);
 	sysfs_del_hardif(&batman_if->hardif_obj);
+	dev_put(batman_if->net_dev);
 	call_rcu(&batman_if->rcu, hardif_free_interface);
 }
 
-- 
1.7.1

[B.A.T.M.A.N.] [PATCH 3/3] Staging: batman-adv: Don't write in not allocated packet_buff

[Sven Eckelmann]

Each net_device in a system will automatically managed as a possible
batman_if and holds different informations like a buffer with a prepared
originator messages. To reduce the memory usage, the packet_buff will
only be allocated when the interface is really added/enabled for
batman-adv.

The function to update the hw address information inside the packet_buff
just assumes that the packet_buff is always initialised and thus the
kernel will just oops when we try to change the hw address of a not
already fully enabled interface.

We must always check if the packet_buff is allocated before we try to
change information inside of it.

Reported-by: Tim Glaremin <Tim.Glaremin@web.de>
Reported-by: Kazuki Shimada <zukky@bb.banban.jp>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
---
 drivers/staging/batman-adv/hard-interface.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c
index d08491e..baa8b05 100644
--- a/drivers/staging/batman-adv/hard-interface.c
+++ b/drivers/staging/batman-adv/hard-interface.c
@@ -129,6 +129,9 @@ static bool hardif_is_iface_up(struct batman_if *batman_if)
 
 static void update_mac_addresses(struct batman_if *batman_if)
 {
+	if (!batman_if || !batman_if->packet_buff)
+		return;
+
 	addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);
 
 	memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
@@ -334,6 +337,7 @@ static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 	batman_if->if_num = -1;
 	batman_if->net_dev = net_dev;
 	batman_if->if_status = IF_NOT_IN_USE;
+	batman_if->packet_buff = NULL;
 	INIT_LIST_HEAD(&batman_if->list);
 
 	check_known_mac_addr(batman_if->net_dev->dev_addr);
-- 
1.7.1

Re: [B.A.T.M.A.N.] Staging: batman-adv for 2.6.36 (7: fixes)

[Greg KH]

On Sat, Aug 21, 2010 at 02:18:07PM +0200, Sven Eckelmann wrote:
> Hi,
> 
> here are patches targeted for 2.6.36. They are smaller bugfixes and add
> no new features.
> 
> I already send you 5 Patches two weeks ago which fixes problems in 2.6.36 and
> one of them also in 2.6.35, but got no reply till now. So here is the reminder
> you asked me before.

Sorry about that, they are all queued up now.

thanks,

greg k-h