--- a/fs/namespace.c	2022-05-16 19:34:10.676163000 +0800
+++ j/fs/namespace.c	2022-05-18 18:38:01.165374300 +0800
@@ -1221,10 +1221,16 @@ static void mntput_no_expire(struct moun
 		 * we are dropping is not the final one.
 		 */
 		mnt_add_count(mnt, -1);
+		count = mnt_get_count(mnt);
+		WARN_ON(count == 0);
+		WARN_ON(count < 0);
 		rcu_read_unlock();
 		return;
 	}
 	lock_mount_hash();
+	count = mnt_get_count(mnt);
+	WARN_ON(count == 0);
+	WARN_ON(count < 0);
 	/*
 	 * make sure that if __legitimize_mnt() has not seen us grab
 	 * mount_lock, we'll see their refcount increment here.
--- a/include/linux/cgroup-defs.h	2022-05-16 20:01:41.873691800 +0800
+++ j/include/linux/cgroup-defs.h	2022-05-18 18:38:01.178665800 +0800
@@ -179,7 +179,7 @@ struct cgroup_subsys_state {
 	atomic_t online_cnt;
 
 	/* percpu_ref killing and RCU release */
-	struct work_struct destroy_work;
+	struct work_struct destroy_work, release_work;
 	struct rcu_work destroy_rwork;
 
 	/*
--- a/kernel/cgroup/cgroup.c	2022-05-16 20:03:31.595702700 +0800
+++ j/kernel/cgroup/cgroup.c	2022-05-18 18:38:01.194420100 +0800
@@ -5154,7 +5154,7 @@ static void css_free_rwork_fn(struct wor
 static void css_release_work_fn(struct work_struct *work)
 {
 	struct cgroup_subsys_state *css =
-		container_of(work, struct cgroup_subsys_state, destroy_work);
+		container_of(work, struct cgroup_subsys_state, release_work);
 	struct cgroup_subsys *ss = css->ss;
 	struct cgroup *cgrp = css->cgroup;
 
@@ -5210,8 +5210,8 @@ static void css_release(struct percpu_re
 	struct cgroup_subsys_state *css =
 		container_of(ref, struct cgroup_subsys_state, refcnt);
 
-	INIT_WORK(&css->destroy_work, css_release_work_fn);
-	queue_work(cgroup_destroy_wq, &css->destroy_work);
+	INIT_WORK(&css->release_work, css_release_work_fn);
+	queue_work(cgroup_destroy_wq, &css->release_work);
 }
 
 static void init_and_link_css(struct cgroup_subsys_state *css,
--- a/lib/percpu-refcount.c	2022-05-18 18:18:40.337365100 +0800
+++ j/lib/percpu-refcount.c	2022-05-18 18:38:01.215498900 +0800
@@ -76,6 +76,7 @@ int percpu_ref_init(struct percpu_ref *r
 	data = kzalloc(sizeof(*ref->data), gfp);
 	if (!data) {
 		free_percpu((void __percpu *)ref->percpu_count_ptr);
+		ref->percpu_count_ptr = 0;
 		return -ENOMEM;
 	}
 
--- a/net/ipv4/tcp_input.c	2022-05-16 19:59:50.885069300 +0800
+++ j/net/ipv4/tcp_input.c	2022-05-18 18:38:01.244757300 +0800
@@ -5926,6 +5926,7 @@ void tcp_rcv_established(struct sock *sk
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPHITS);
 
 			/* Bulk data transfer: receiver */
+			skb_dst_drop(skb);
 			__skb_pull(skb, tcp_header_len);
 			eaten = tcp_queue_rcv(sk, skb, &fragstolen);