net: force a list_del() in unregister_netdevice_many()
unregister_netdevice_many() API is error prone and we had too
many bugs because of dangling LIST_HEAD on stacks.
See commit f87e6f47933e3e ("net: dont leave active on stack LIST_HEAD")
In fact, instead of making sure no caller leaves an active list_head,
just force a list_del() in the callee. No one seems to need to access
the list after unregister_netdevice_many()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index fb8b054..a30bef1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6613,6 +6613,9 @@
/**
* unregister_netdevice_many - unregister many devices
* @head: list of devices
+ *
+ * Note: As most callers use a stack allocated list_head,
+ * we force a list_del() to make sure stack wont be corrupted later.
*/
void unregister_netdevice_many(struct list_head *head)
{
@@ -6622,6 +6625,7 @@
rollback_registered_many(head);
list_for_each_entry(dev, head, unreg_list)
net_set_todo(dev);
+ list_del(head);
}
}
EXPORT_SYMBOL(unregister_netdevice_many);
@@ -7077,7 +7081,6 @@
}
}
unregister_netdevice_many(&dev_kill_list);
- list_del(&dev_kill_list);
rtnl_unlock();
}