mac80211: don't allow registering the same rate control twice
Previously, mac80211 would allow registering the same rate control
algorithm twice. This is a programming error in the registration
and should not happen; additionally the second version could never
be selected. Disallow this and warn about it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_rate.c b/net/mac80211/ieee80211_rate.c
index e4bd848..7254bd6 100644
--- a/net/mac80211/ieee80211_rate.c
+++ b/net/mac80211/ieee80211_rate.c
@@ -28,13 +28,22 @@
if (!ops->name)
return -EINVAL;
+ mutex_lock(&rate_ctrl_mutex);
+ list_for_each_entry(alg, &rate_ctrl_algs, list) {
+ if (!strcmp(alg->ops->name, ops->name)) {
+ /* don't register an algorithm twice */
+ WARN_ON(1);
+ return -EALREADY;
+ }
+ }
+
alg = kzalloc(sizeof(*alg), GFP_KERNEL);
if (alg == NULL) {
+ mutex_unlock(&rate_ctrl_mutex);
return -ENOMEM;
}
alg->ops = ops;
- mutex_lock(&rate_ctrl_mutex);
list_add_tail(&alg->list, &rate_ctrl_algs);
mutex_unlock(&rate_ctrl_mutex);