[NET]: Take dev_base_lock when moving device name hash list entry
When we added name-based hashing the dev_base_lock was designated as the
lock to take when changing the name hash list. Unfortunately, because
it was a preexisting lock that just happened to be taken in the right
spots we neglected to take it in dev_change_name.
The race can affect calles of __dev_get_by_name that do so without taking
the RTNL. They may end up walking down the wrong hash chain and end up
missing the device that they're looking for.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 7bfea5e..346cbf6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -839,8 +839,12 @@
strlcpy(dev->name, newname, IFNAMSIZ);
device_rename(&dev->dev, dev->name);
+
+ write_lock_bh(&dev_base_lock);
hlist_del(&dev->name_hlist);
hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name));
+ write_unlock_bh(&dev_base_lock);
+
raw_notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);
return err;