redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

Staging: batman-adv: Don't use net_dev after dev_put

Browse source 
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Sven Eckelmann 2010-08-21 14:18:09 +02:00 committed by Greg Kroah-Hartman
parent 1189f130f8
commit 51a00eaf6e
1 changed files with 6 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
drivers/staging/batman-adv/hard-interface.c
View file

@ -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);
}