From 5c0c36412b2dc6b1e243c7e9115306fe286583b7 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 12 May 2011 14:31:49 +0200 Subject: mac80211: make key locking clearer The code in ieee80211_del_key() doesn't acquire the key_mtx properly when it dereferences the keys. It turns out that isn't actually necessary since the key_mtx itself seems to be redundant since all key manipulations are done under the RTNL, but as long as we have the key_mtx we should use it the right way too. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/cfg.c | 38 +++++++++++++++----------------------- net/mac80211/key.c | 8 ++++---- net/mac80211/key.h | 1 + 3 files changed, 20 insertions(+), 27 deletions(-) diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index ed3400cd7a5a..94690366321c 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -160,13 +160,14 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev, static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev, u8 key_idx, bool pairwise, const u8 *mac_addr) { - struct ieee80211_sub_if_data *sdata; + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct ieee80211_local *local = sdata->local; struct sta_info *sta; + struct ieee80211_key *key = NULL; int ret; - sdata = IEEE80211_DEV_TO_SUB_IF(dev); - - mutex_lock(&sdata->local->sta_mtx); + mutex_lock(&local->sta_mtx); + mutex_lock(&local->key_mtx); if (mac_addr) { ret = -ENOENT; @@ -175,33 +176,24 @@ static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev, if (!sta) goto out_unlock; - if (pairwise) { - if (sta->ptk) { - ieee80211_key_free(sdata->local, sta->ptk); - ret = 0; - } - } else { - if (sta->gtk[key_idx]) { - ieee80211_key_free(sdata->local, - sta->gtk[key_idx]); - ret = 0; - } - } - - goto out_unlock; - } + if (pairwise) + key = sta->ptk; + else + key = sta->gtk[key_idx]; + } else + key = sdata->keys[key_idx]; - if (!sdata->keys[key_idx]) { + if (!key) { ret = -ENOENT; goto out_unlock; } - ieee80211_key_free(sdata->local, sdata->keys[key_idx]); - WARN_ON(sdata->keys[key_idx]); + __ieee80211_key_free(key); ret = 0; out_unlock: - mutex_unlock(&sdata->local->sta_mtx); + mutex_unlock(&local->key_mtx); + mutex_unlock(&local->sta_mtx); return ret; } diff --git a/net/mac80211/key.c b/net/mac80211/key.c index b510721e3b3d..958832dd4f0a 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -471,8 +471,11 @@ int ieee80211_key_link(struct ieee80211_key *key, return ret; } -static void __ieee80211_key_free(struct ieee80211_key *key) +void __ieee80211_key_free(struct ieee80211_key *key) { + if (!key) + return; + /* * Replace key with nothingness if it was ever used. */ @@ -486,9 +489,6 @@ static void __ieee80211_key_free(struct ieee80211_key *key) void ieee80211_key_free(struct ieee80211_local *local, struct ieee80211_key *key) { - if (!key) - return; - mutex_lock(&local->key_mtx); __ieee80211_key_free(key); mutex_unlock(&local->key_mtx); diff --git a/net/mac80211/key.h b/net/mac80211/key.h index 4ddbe27eb570..e5432ef8b203 100644 --- a/net/mac80211/key.h +++ b/net/mac80211/key.h @@ -135,6 +135,7 @@ struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len, int __must_check ieee80211_key_link(struct ieee80211_key *key, struct ieee80211_sub_if_data *sdata, struct sta_info *sta); +void __ieee80211_key_free(struct ieee80211_key *key); void ieee80211_key_free(struct ieee80211_local *local, struct ieee80211_key *key); void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx, -- cgit v1.2.3