mac80211: fix CMAC races
Just like TKIP and CCMP, CMAC has the PN race.
It might not actually be possible to hit it now
since there aren't multiple ACs for management
frames, but fix it anyway.
Also move scratch buffers onto the stack.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 7691e4e..3452d5e 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -523,6 +523,16 @@
}
+static inline void bip_ipn_set64(u8 *d, u64 pn)
+{
+ *d++ = pn;
+ *d++ = pn >> 8;
+ *d++ = pn >> 16;
+ *d++ = pn >> 24;
+ *d++ = pn >> 32;
+ *d = pn >> 40;
+}
+
static inline void bip_ipn_swap(u8 *d, const u8 *s)
{
*d++ = s[5];
@@ -541,8 +551,8 @@
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_key *key = tx->key;
struct ieee80211_mmie *mmie;
- u8 *pn, aad[20];
- int i;
+ u8 aad[20];
+ u64 pn64;
if (info->control.hw_key)
return 0;
@@ -556,22 +566,17 @@
mmie->key_id = cpu_to_le16(key->conf.keyidx);
/* PN = PN + 1 */
- pn = key->u.aes_cmac.tx_pn;
+ pn64 = atomic64_inc_return(&key->u.aes_cmac.tx_pn);
- for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) {
- pn[i]++;
- if (pn[i])
- break;
- }
- bip_ipn_swap(mmie->sequence_number, pn);
+ bip_ipn_set64(mmie->sequence_number, pn64);
bip_aad(skb, aad);
/*
* MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
*/
- ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf,
- aad, skb->data + 24, skb->len - 24, mmie->mic);
+ ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
+ skb->data + 24, skb->len - 24, mmie->mic);
return TX_CONTINUE;
}
@@ -609,8 +614,7 @@
if (!(status->flag & RX_FLAG_DECRYPTED)) {
/* hardware didn't decrypt/verify MIC */
bip_aad(skb, aad);
- ieee80211_aes_cmac(key->u.aes_cmac.tfm,
- key->u.aes_cmac.rx_crypto_buf, aad,
+ ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mic);
if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
key->u.aes_cmac.icverrors++;