commit 5e819049c270f4771bb990db13d75f8ec88f6227
Author: Victor Nogueira <victor@mojatatu.com>
Date:   Mon Apr 15 12:10:40 2024 +0000

    Mirred nested loop fix

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 76db6be16083..f561dfb79743 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -117,6 +117,7 @@ struct Qdisc {
 	struct qdisc_skb_head	q;
 	struct gnet_stats_basic_sync bstats;
 	struct gnet_stats_queue	qstats;
+	int                     owner;
 	unsigned long		state;
 	unsigned long		state2; /* must be written under qdisc spinlock */
 	struct Qdisc            *next_sched;
diff --git a/net/core/dev.c b/net/core/dev.c
index 854a3a28a8d8..f6c6e494f0a9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3808,6 +3808,10 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 		return rc;
 	}
 
+	if (unlikely(READ_ONCE(q->owner) == smp_processor_id())) {
+		kfree_skb_reason(skb, SKB_DROP_REASON_TC_RECLASSIFY_LOOP);
+		return NET_XMIT_DROP;
+	}
 	/*
 	 * Heuristic to force contended enqueues to serialize on a
 	 * separate lock before trying to get qdisc main lock.
@@ -3847,7 +3851,9 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 		qdisc_run_end(q);
 		rc = NET_XMIT_SUCCESS;
 	} else {
+		WRITE_ONCE(q->owner, smp_processor_id());
 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
+		WRITE_ONCE(q->owner, -1);
 		if (qdisc_run_begin(q)) {
 			if (unlikely(contended)) {
 				spin_unlock(&q->busylock);
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 60239378d43f..15c715c16247 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1376,6 +1376,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
 		}
 	}
 
+	sch->owner = -1;
 	qdisc_hash_add(sch, false);
 	trace_qdisc_create(ops, dev, parent);