[PATCH] ieee80211: Fix TKIP and WEP decryption error on SMP machines

The IEEE80211 TKIP and WEP Tx and Rx paths use the same crypto_tfm to encrypt
and decrypt data. During the encrypt and decrypt process, both of them will
set a new key to crypto_tfm. If they happen on the same time, it will
corrupt the crypto_tfm. Thus users will receive an ICV error or Michael MIC
error. This only likely to happen on SMP box with heavy traffic both on Tx
and Rx. The patch use two sets of crypto_tfms to avoid this problem.

Signed-off-by: Hong Liu <hong.liu@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/ieee80211/ieee80211_crypt_tkip.c b/net/ieee80211/ieee80211_crypt_tkip.c
index 02abf29..f2df2f5 100644
--- a/net/ieee80211/ieee80211_crypt_tkip.c
+++ b/net/ieee80211/ieee80211_crypt_tkip.c
@@ -52,8 +52,10 @@
 
 	int key_idx;
 
-	struct crypto_tfm *tfm_arc4;
-	struct crypto_tfm *tfm_michael;
+	struct crypto_tfm *tx_tfm_arc4;
+	struct crypto_tfm *tx_tfm_michael;
+	struct crypto_tfm *rx_tfm_arc4;
+	struct crypto_tfm *rx_tfm_michael;
 
 	/* scratch buffers for virt_to_page() (crypto API) */
 	u8 rx_hdr[16], tx_hdr[16];
@@ -85,15 +87,29 @@
 
 	priv->key_idx = key_idx;
 
-	priv->tfm_arc4 = crypto_alloc_tfm("arc4", 0);
-	if (priv->tfm_arc4 == NULL) {
+	priv->tx_tfm_arc4 = crypto_alloc_tfm("arc4", 0);
+	if (priv->tx_tfm_arc4 == NULL) {
 		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
 		       "crypto API arc4\n");
 		goto fail;
 	}
 
-	priv->tfm_michael = crypto_alloc_tfm("michael_mic", 0);
-	if (priv->tfm_michael == NULL) {
+	priv->tx_tfm_michael = crypto_alloc_tfm("michael_mic", 0);
+	if (priv->tx_tfm_michael == NULL) {
+		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
+		       "crypto API michael_mic\n");
+		goto fail;
+	}
+
+	priv->rx_tfm_arc4 = crypto_alloc_tfm("arc4", 0);
+	if (priv->rx_tfm_arc4 == NULL) {
+		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
+		       "crypto API arc4\n");
+		goto fail;
+	}
+
+	priv->rx_tfm_michael = crypto_alloc_tfm("michael_mic", 0);
+	if (priv->rx_tfm_michael == NULL) {
 		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
 		       "crypto API michael_mic\n");
 		goto fail;
@@ -103,10 +119,14 @@
 
       fail:
 	if (priv) {
-		if (priv->tfm_michael)
-			crypto_free_tfm(priv->tfm_michael);
-		if (priv->tfm_arc4)
-			crypto_free_tfm(priv->tfm_arc4);
+		if (priv->tx_tfm_michael)
+			crypto_free_tfm(priv->tx_tfm_michael);
+		if (priv->tx_tfm_arc4)
+			crypto_free_tfm(priv->tx_tfm_arc4);
+		if (priv->rx_tfm_michael)
+			crypto_free_tfm(priv->rx_tfm_michael);
+		if (priv->rx_tfm_arc4)
+			crypto_free_tfm(priv->rx_tfm_arc4);
 		kfree(priv);
 	}
 
@@ -116,10 +136,16 @@
 static void ieee80211_tkip_deinit(void *priv)
 {
 	struct ieee80211_tkip_data *_priv = priv;
-	if (_priv && _priv->tfm_michael)
-		crypto_free_tfm(_priv->tfm_michael);
-	if (_priv && _priv->tfm_arc4)
-		crypto_free_tfm(_priv->tfm_arc4);
+	if (_priv) {
+		if (_priv->tx_tfm_michael)
+			crypto_free_tfm(_priv->tx_tfm_michael);
+		if (_priv->tx_tfm_arc4)
+			crypto_free_tfm(_priv->tx_tfm_arc4);
+		if (_priv->rx_tfm_michael)
+			crypto_free_tfm(_priv->rx_tfm_michael);
+		if (_priv->rx_tfm_arc4)
+			crypto_free_tfm(_priv->rx_tfm_arc4);
+	}
 	kfree(priv);
 }
 
@@ -351,11 +377,11 @@
 	icv[2] = crc >> 16;
 	icv[3] = crc >> 24;
 
-	crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16);
+	crypto_cipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
 	sg.page = virt_to_page(pos);
 	sg.offset = offset_in_page(pos);
 	sg.length = len + 4;
-	crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4);
+	crypto_cipher_encrypt(tkey->tx_tfm_arc4, &sg, &sg, len + 4);
 
 	return 0;
 }
@@ -446,11 +472,11 @@
 
 	plen = skb->len - hdr_len - 12;
 
-	crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16);
+	crypto_cipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
 	sg.page = virt_to_page(pos);
 	sg.offset = offset_in_page(pos);
 	sg.length = plen + 4;
-	crypto_cipher_decrypt(tkey->tfm_arc4, &sg, &sg, plen + 4);
+	crypto_cipher_decrypt(tkey->rx_tfm_arc4, &sg, &sg, plen + 4);
 
 	crc = ~crc32_le(~0, pos, plen);
 	icv[0] = crc;
@@ -484,12 +510,12 @@
 	return keyidx;
 }
 
-static int michael_mic(struct ieee80211_tkip_data *tkey, u8 * key, u8 * hdr,
+static int michael_mic(struct crypto_tfm *tfm_michael, u8 * key, u8 * hdr,
 		       u8 * data, size_t data_len, u8 * mic)
 {
 	struct scatterlist sg[2];
 
-	if (tkey->tfm_michael == NULL) {
+	if (tfm_michael == NULL) {
 		printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
 		return -1;
 	}
@@ -501,10 +527,10 @@
 	sg[1].offset = offset_in_page(data);
 	sg[1].length = data_len;
 
-	crypto_digest_init(tkey->tfm_michael);
-	crypto_digest_setkey(tkey->tfm_michael, key, 8);
-	crypto_digest_update(tkey->tfm_michael, sg, 2);
-	crypto_digest_final(tkey->tfm_michael, mic);
+	crypto_digest_init(tfm_michael);
+	crypto_digest_setkey(tfm_michael, key, 8);
+	crypto_digest_update(tfm_michael, sg, 2);
+	crypto_digest_final(tfm_michael, mic);
 
 	return 0;
 }
@@ -562,7 +588,7 @@
 
 	michael_mic_hdr(skb, tkey->tx_hdr);
 	pos = skb_put(skb, 8);
-	if (michael_mic(tkey, &tkey->key[16], tkey->tx_hdr,
+	if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
 			skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
 		return -1;
 
@@ -600,7 +626,7 @@
 		return -1;
 
 	michael_mic_hdr(skb, tkey->rx_hdr);
-	if (michael_mic(tkey, &tkey->key[24], tkey->rx_hdr,
+	if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
 			skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
 		return -1;
 	if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
@@ -630,14 +656,18 @@
 {
 	struct ieee80211_tkip_data *tkey = priv;
 	int keyidx;
-	struct crypto_tfm *tfm = tkey->tfm_michael;
-	struct crypto_tfm *tfm2 = tkey->tfm_arc4;
+	struct crypto_tfm *tfm = tkey->tx_tfm_michael;
+	struct crypto_tfm *tfm2 = tkey->tx_tfm_arc4;
+	struct crypto_tfm *tfm3 = tkey->rx_tfm_michael;
+	struct crypto_tfm *tfm4 = tkey->rx_tfm_arc4;
 
 	keyidx = tkey->key_idx;
 	memset(tkey, 0, sizeof(*tkey));
 	tkey->key_idx = keyidx;
-	tkey->tfm_michael = tfm;
-	tkey->tfm_arc4 = tfm2;
+	tkey->tx_tfm_michael = tfm;
+	tkey->tx_tfm_arc4 = tfm2;
+	tkey->rx_tfm_michael = tfm3;
+	tkey->rx_tfm_arc4 = tfm4;
 	if (len == TKIP_KEY_LEN) {
 		memcpy(tkey->key, key, TKIP_KEY_LEN);
 		tkey->key_set = 1;