[B.A.T.M.A.N.] [PATCH] batman-adv: Fix crash on module shutdown with multiple ifaces

Linus Lüssing
2011-04-15T18:24:42Z

hardif_remove_interfaces() removes all hard interfaces from the
hardif_list before freeing and cleaning up any device. However the clean
up procedures in orig_hash_del_if()
(hardif_remove_interface()->hardif_disable_interface()->
orig_hash_del_if())
need the other interfaces still to be present in the hardif_list.
Otherwise it won't renumber any preceding interfaces, which leads to an
unhandled kernel paging request in orig_node_del_if()'s "/* copy second
part */" due to wrong hard_if->if_num's.

With this commit the interface removal on module shutdown will be down
in the same way as removing single interfaces from batman only: One
interface will be removed and cleaned at a time.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
hard-interface.c | 15 ++++-----------
1 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/hard-interface.c b/hard-interface.c
index b3058e4..f039a3d 100644
--- a/hard-interface.c
+++ b/hard-interface.c
@@ -490,20 +490,13 @@ static void hardif_remove_interface(struct hard_iface *hard_iface)
void hardif_remove_interfaces(void)
{
struct hard_iface *hard_iface, *hard_iface_tmp;
- struct list_head if_queue;

- INIT_LIST_HEAD(&if_queue);
-
- spin_lock(&hardif_list_lock);
- list_for_each_entry_safe(hard_iface, hard_iface_tmp,
- &hardif_list, list) {
+ rtnl_lock();
+ list_for_each_entry_safe(hard_iface, hard_iface_tmp, &hardif_list, list) {
+ spin_lock(&hardif_list_lock);
list_del_rcu(&hard_iface->list);
- list_add_tail(&hard_iface->list, &if_queue);
- }
- spin_unlock(&hardif_list_lock);
+ spin_unlock(&hardif_list_lock);

- rtnl_lock();
- list_for_each_entry_safe(hard_iface, hard_iface_tmp, &if_queue, list) {
hardif_remove_interface(hard_iface);
}
rtnl_unlock();
--
1.7.4.1