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path: root/package/mac80211/patches/420-mac80211_ignore_invalid_ccmp_rx_pn.patch
blob: f6793541f2aaa60480939a492468ca4f1ecc3858 (plain)
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--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -86,6 +86,7 @@ struct ieee80211_key {
 			 * Management frames.
 			 */
 			u8 rx_pn[NUM_RX_DATA_QUEUES + 1][6];
+			u8 rx_invalid_pn[NUM_RX_DATA_QUEUES + 1];
 			struct crypto_cipher *tfm;
 			u32 replays; /* dot11RSNAStatsCCMPReplays */
 			/* scratch buffers for virt_to_page() (crypto API) */
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -441,6 +441,13 @@ ieee80211_crypto_ccmp_encrypt(struct iee
 	return TX_CONTINUE;
 }
 
+static inline u64 pn_to_u64(u8 *data)
+{
+	u64 pn = get_unaligned_be32(data + 2);
+	pn |= ((u64) get_unaligned_be16(data)) << 32;
+	return pn;
+}
+
 
 ieee80211_rx_result
 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
@@ -453,6 +460,7 @@ ieee80211_crypto_ccmp_decrypt(struct iee
 	u8 pn[CCMP_PN_LEN];
 	int data_len;
 	int queue;
+	u64 diff;
 
 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
 
@@ -486,6 +494,11 @@ ieee80211_crypto_ccmp_decrypt(struct iee
 			return RX_DROP_UNUSABLE;
 	}
 
+	diff = pn_to_u64(pn) - pn_to_u64(key->u.ccmp.rx_pn[queue]);
+	if (diff > 1000 && key->u.ccmp.rx_invalid_pn[queue]++ < 10)
+		return RX_DROP_UNUSABLE;
+
+	key->u.ccmp.rx_invalid_pn[queue] = 0;
 	memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN);
 
 	/* Remove CCMP header and MIC */