mac80211 : fix a race with update_tkip_key

The mac80211 tkip code won't call update_tkip_key, if rx packets
are received without KEY_FLAG_UPLOADED_TO_HARDWARE. This can happen on
first packet because the hardware key stuff is called asynchronously with
todo workqueue.

This patch workaround that by tracking if we sent the key to the driver.

Signed-off-by: Gregor Kowski <gregor.kowski@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c
index 4921d72..b73454a 100644
--- a/net/mac80211/tkip.c
+++ b/net/mac80211/tkip.c
@@ -100,7 +100,7 @@
 		p1k[3] += tkipS(p1k[2] ^ get_unaligned_le16(tk + 12 + j));
 		p1k[4] += tkipS(p1k[3] ^ get_unaligned_le16(tk + 0 + j)) + i;
 	}
-	ctx->initialized = 1;
+	ctx->state = TKIP_STATE_PHASE1_DONE;
 }
 
 static void tkip_mixing_phase2(const u8 *tk, struct tkip_ctx *ctx,
@@ -183,7 +183,7 @@
 	/* Update the p1k only when the iv16 in the packet wraps around, this
 	 * might occur after the wrap around of iv16 in the key in case of
 	 * fragmented packets. */
-	if (iv16 == 0 || !ctx->initialized)
+	if (iv16 == 0 || ctx->state == TKIP_STATE_NOT_INIT)
 		tkip_mixing_phase1(tk, ctx, hdr->addr2, iv32);
 
 	if (type == IEEE80211_TKIP_P1_KEY) {
@@ -209,7 +209,7 @@
 	const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
 
 	/* Calculate per-packet key */
-	if (ctx->iv16 == 0 || !ctx->initialized)
+	if (ctx->iv16 == 0 || ctx->state == TKIP_STATE_NOT_INIT)
 		tkip_mixing_phase1(tk, ctx, ta, ctx->iv32);
 
 	tkip_mixing_phase2(tk, ctx, ctx->iv16, rc4key);
@@ -259,7 +259,7 @@
 	if ((keyid >> 6) != key->conf.keyidx)
 		return TKIP_DECRYPT_INVALID_KEYIDX;
 
-	if (key->u.tkip.rx[queue].initialized &&
+	if (key->u.tkip.rx[queue].state != TKIP_STATE_NOT_INIT &&
 	    (iv32 < key->u.tkip.rx[queue].iv32 ||
 	     (iv32 == key->u.tkip.rx[queue].iv32 &&
 	      iv16 <= key->u.tkip.rx[queue].iv16))) {
@@ -275,11 +275,11 @@
 
 	if (only_iv) {
 		res = TKIP_DECRYPT_OK;
-		key->u.tkip.rx[queue].initialized = 1;
+		key->u.tkip.rx[queue].state = TKIP_STATE_PHASE1_HW_UPLOADED;
 		goto done;
 	}
 
-	if (!key->u.tkip.rx[queue].initialized ||
+	if (key->u.tkip.rx[queue].state == TKIP_STATE_NOT_INIT ||
 	    key->u.tkip.rx[queue].iv32 != iv32) {
 		/* IV16 wrapped around - perform TKIP phase 1 */
 		tkip_mixing_phase1(tk, &key->u.tkip.rx[queue], ta, iv32);
@@ -299,18 +299,20 @@
 			printk("\n");
 		}
 #endif
-		if (key->local->ops->update_tkip_key &&
-			key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
-			static const u8 bcast[ETH_ALEN] =
-				{0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
-			const u8 *sta_addr = key->sta->sta.addr;
+	}
+	if (key->local->ops->update_tkip_key &&
+	    key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE &&
+	    key->u.tkip.rx[queue].state != TKIP_STATE_PHASE1_HW_UPLOADED) {
+		static const u8 bcast[ETH_ALEN] =
+		{0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+		const u8 *sta_addr = key->sta->sta.addr;
 
-			if (is_multicast_ether_addr(ra))
-				sta_addr = bcast;
+		if (is_multicast_ether_addr(ra))
+			sta_addr = bcast;
 
-			drv_update_tkip_key(key->local, &key->conf, sta_addr,
-					    iv32, key->u.tkip.rx[queue].p1k);
-		}
+		drv_update_tkip_key(key->local, &key->conf, sta_addr,
+				iv32, key->u.tkip.rx[queue].p1k);
+		key->u.tkip.rx[queue].state = TKIP_STATE_PHASE1_HW_UPLOADED;
 	}
 
 	tkip_mixing_phase2(tk, &key->u.tkip.rx[queue], iv16, rc4key);