From 32162a4dab0e6a4ca7f886a01173b5f9b80843be Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Mon, 26 Jul 2010 15:52:03 -0700 Subject: mac80211: Fix key freeing to handle unlinked keys Key locking simplification removed key->sdata != NULL verification from ieee80211_key_free(). While that is fine for most use cases, there is one path where this function can be called with an unlinked key (i.e., key->sdata == NULL && key->local == NULL). This results in a NULL pointer dereference with the current implementation. This is known to happen at least with FT protocol when wpa_supplicant tries to configure the key before association. Avoid the issue by passing in the local pointer to ieee80211_key_free(). In addition, do not clear the key from hw_accel or debugfs if it has not yet been added. At least the hw_accel one could trigger another NULL pointer dereference. Signed-off-by: Jouni Malinen Reviewed-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/key.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'net/mac80211/key.c') diff --git a/net/mac80211/key.c b/net/mac80211/key.c index 50d1cff23d8..1b9d87ed143 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -323,13 +323,15 @@ static void __ieee80211_key_destroy(struct ieee80211_key *key) if (!key) return; - ieee80211_key_disable_hw_accel(key); + if (key->local) + ieee80211_key_disable_hw_accel(key); if (key->conf.alg == ALG_CCMP) ieee80211_aes_key_free(key->u.ccmp.tfm); if (key->conf.alg == ALG_AES_CMAC) ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm); - ieee80211_debugfs_key_remove(key); + if (key->local) + ieee80211_debugfs_key_remove(key); kfree(key); } @@ -410,15 +412,12 @@ static void __ieee80211_key_free(struct ieee80211_key *key) __ieee80211_key_destroy(key); } -void ieee80211_key_free(struct ieee80211_key *key) +void ieee80211_key_free(struct ieee80211_local *local, + struct ieee80211_key *key) { - struct ieee80211_local *local; - if (!key) return; - local = key->sdata->local; - mutex_lock(&local->key_mtx); __ieee80211_key_free(key); mutex_unlock(&local->key_mtx); -- cgit v1.2.3-18-g5258