1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 3b1f0bb6a414..f0044329e3d7 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -675,6 +675,7 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
 			return err;
 
 		OCELOT_SKB_CB(skb)->ptp_cmd = ptp_cmd;
+		OCELOT_SKB_CB(*clone)->ptp_class = ptp_class;
 	}
 
 	return 0;
@@ -708,6 +709,17 @@ static void ocelot_get_hwtimestamp(struct ocelot *ocelot,
 	spin_unlock_irqrestore(&ocelot->ptp_clock_lock, flags);
 }
 
+static bool ocelot_validate_ptp_skb(struct sk_buff *clone, u16 seqid)
+{
+	struct ptp_header *hdr;
+
+	hdr = ptp_parse_header(clone, OCELOT_SKB_CB(clone)->ptp_class);
+	if (WARN_ON(!hdr))
+		return false;
+
+	return seqid == ntohs(hdr->sequence_id);
+}
+
 void ocelot_get_txtstamp(struct ocelot *ocelot)
 {
 	int budget = OCELOT_PTP_QUEUE_SZ;
@@ -715,10 +727,10 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 	while (budget--) {
 		struct sk_buff *skb, *skb_tmp, *skb_match = NULL;
 		struct skb_shared_hwtstamps shhwtstamps;
+		u32 val, id, seqid, txport;
 		struct ocelot_port *port;
 		struct timespec64 ts;
 		unsigned long flags;
-		u32 val, id, txport;
 
 		val = ocelot_read(ocelot, SYS_PTP_STATUS);
 
@@ -731,6 +743,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 		/* Retrieve the ts ID and Tx port */
 		id = SYS_PTP_STATUS_PTP_MESS_ID_X(val);
 		txport = SYS_PTP_STATUS_PTP_MESS_TXPORT_X(val);
+		seqid = SYS_PTP_STATUS_PTP_MESS_SEQ_ID(val);
 
 		port = ocelot->ports[txport];
 
@@ -740,6 +753,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 		spin_unlock(&ocelot->ts_id_lock);
 
 		/* Retrieve its associated skb */
+try_again:
 		spin_lock_irqsave(&port->tx_skbs.lock, flags);
 
 		skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) {
@@ -755,6 +769,14 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 		if (WARN_ON(!skb_match))
 			continue;
 
+		if (!ocelot_validate_ptp_skb(skb_match, seqid)) {
+			dev_err_ratelimited(ocelot->dev,
+					    "port %d received stale TX timestamp for seqid %d, discarding\n",
+					    txport, seqid);
+			dev_kfree_skb_any(skb);
+			goto try_again;
+		}
+
 		/* Get the h/w timestamp */
 		ocelot_get_hwtimestamp(ocelot, &ts);