When a wdev changes network namespace, its wdev ID will get reassigned since NETDEV_REGISTER is called again, in the new network namespace. Avoid that by checking if it was already assigned before, and document why we do that. Reported-and-tested-by: Arend Van Spriel <arend.vanspriel@xxxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> --- net/wireless/core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/net/wireless/core.c b/net/wireless/core.c index b1a028d381ef..b0d6761f0cdd 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -1159,7 +1159,15 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb, INIT_LIST_HEAD(&wdev->mgmt_registrations); spin_lock_init(&wdev->mgmt_registrations_lock); - wdev->identifier = ++rdev->wdev_id; + /* + * We get here also when the interface changes network namespaces, + * as it's registered into the new one, but we don't want it to + * change ID in that case. Checking if the ID is already assigned + * works, because 0 isn't considered a valid ID and the memory is + * 0-initialized. + */ + if (!wdev->identifier) + wdev->identifier = ++rdev->wdev_id; list_add_rcu(&wdev->list, &rdev->wiphy.wdev_list); rdev->devlist_generation++; /* can only change netns with wiphy */ -- 2.11.0
