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authorJohannes Berg <johannes@sipsolutions.net>2017-03-17 10:24:15 +0100
committerJohannes Berg <johannes.berg@intel.com>2017-03-17 11:39:55 +0100
commitb6ecfd469e82886308b44bf715d48fbe7b19ad4c (patch)
treeb652bf22e80e53e555c1e39fae735f6dc58243f4 /net/wireless/core.c
parent335d534938d327d5ba266564b7e6beaf5d456dd2 (diff)
downloadlinux-b6ecfd469e82886308b44bf715d48fbe7b19ad4c.tar.bz2
cfg80211: preserve wdev ID across netns changes
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@broadcom.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/core.c')
-rw-r--r--net/wireless/core.c10
1 files changed, 9 insertions, 1 deletions
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 */