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-rw-r--r--net/mac80211/key.c54
1 files changed, 50 insertions, 4 deletions
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index a98fc2b5e0dc..938049395f90 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -4,7 +4,7 @@
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
- * Copyright 2015 Intel Deutschland GmbH
+ * Copyright 2015-2017 Intel Deutschland GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -19,6 +19,7 @@
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
+#include <crypto/algapi.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
@@ -609,6 +610,39 @@ void ieee80211_key_free_unused(struct ieee80211_key *key)
ieee80211_key_free_common(key);
}
+static bool ieee80211_key_identical(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_key *old,
+ struct ieee80211_key *new)
+{
+ u8 tkip_old[WLAN_KEY_LEN_TKIP], tkip_new[WLAN_KEY_LEN_TKIP];
+ u8 *tk_old, *tk_new;
+
+ if (!old || new->conf.keylen != old->conf.keylen)
+ return false;
+
+ tk_old = old->conf.key;
+ tk_new = new->conf.key;
+
+ /*
+ * In station mode, don't compare the TX MIC key, as it's never used
+ * and offloaded rekeying may not care to send it to the host. This
+ * is the case in iwlwifi, for example.
+ */
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+ new->conf.cipher == WLAN_CIPHER_SUITE_TKIP &&
+ new->conf.keylen == WLAN_KEY_LEN_TKIP &&
+ !(new->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
+ memcpy(tkip_old, tk_old, WLAN_KEY_LEN_TKIP);
+ memcpy(tkip_new, tk_new, WLAN_KEY_LEN_TKIP);
+ memset(tkip_old + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8);
+ memset(tkip_new + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8);
+ tk_old = tkip_old;
+ tk_new = tkip_new;
+ }
+
+ return !crypto_memneq(tk_old, tk_new, new->conf.keylen);
+}
+
int ieee80211_key_link(struct ieee80211_key *key,
struct ieee80211_sub_if_data *sdata,
struct sta_info *sta)
@@ -620,9 +654,6 @@ int ieee80211_key_link(struct ieee80211_key *key,
pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
idx = key->conf.keyidx;
- key->local = sdata->local;
- key->sdata = sdata;
- key->sta = sta;
mutex_lock(&sdata->local->key_mtx);
@@ -633,6 +664,20 @@ int ieee80211_key_link(struct ieee80211_key *key,
else
old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
+ /*
+ * Silently accept key re-installation without really installing the
+ * new version of the key to avoid nonce reuse or replay issues.
+ */
+ if (ieee80211_key_identical(sdata, old_key, key)) {
+ ieee80211_key_free_unused(key);
+ ret = 0;
+ goto out;
+ }
+
+ key->local = sdata->local;
+ key->sdata = sdata;
+ key->sta = sta;
+
increment_tailroom_need_count(sdata);
ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
@@ -648,6 +693,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
ret = 0;
}
+ out:
mutex_unlock(&sdata->local->key_mtx);
return ret;