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mac80211: Fix key freeing to handle unlinked keys

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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 <j@w1.fi>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Jouni Malinen 2010-07-26 15:52:03 -07:00 committed by John W. Linville
parent 1b2fb7dc71
commit 32162a4dab
4 changed files with 12 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
net/mac80211/cfg.c
View File

@ -158,7 +158,7 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
if (mac_addr) {
sta = sta_info_get_bss(sdata, mac_addr);
if (!sta) {
ieee80211_key_free(key);
ieee80211_key_free(sdata->local, key);
err = -ENOENT;
goto out_unlock;
}
@ -192,7 +192,7 @@ static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
goto out_unlock;
if (sta->key) {
ieee80211_key_free(sta->key);
ieee80211_key_free(sdata->local, sta->key);
WARN_ON(sta->key);
ret = 0;
}
@ -205,7 +205,7 @@ static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
goto out_unlock;
}
ieee80211_key_free(sdata->keys[key_idx]);
ieee80211_key_free(sdata->local, sdata->keys[key_idx]);
WARN_ON(sdata->keys[key_idx]);
ret = 0;

13
net/mac80211/key.c
View File

@ -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);

3
net/mac80211/key.h
View File

@ -135,7 +135,8 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
void 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);
void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
int idx);

2
net/mac80211/sta_info.c
View File

@ -647,7 +647,7 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
return ret;
if (sta->key) {
ieee80211_key_free(sta->key);
ieee80211_key_free(local, sta->key);
WARN_ON(sta->key);
}