diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 7a631a257613..3754d697854b 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -527,7 +527,10 @@ struct cgroup {
 
 	int nr_threaded_children;	/* # of live threaded child cgroups */
 
-	/* sequence number for cgroup.kill, serialized by css_set_lock. */
+	/*
+	 * Sequence number for cgroup.kill. Incremented with both cgroup_mutex
+	 * and css_set_lock held. Readers hold either one.
+	 */
 	unsigned int kill_seq;
 
 	struct kernfs_node *kn;		/* cgroup kernfs entry */
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index f87fc4550081..353c8f83439a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6777,10 +6777,7 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
 	spin_lock_irq(&css_set_lock);
 	cset = task_css_set(current);
 	get_css_set(cset);
-	if (kargs->cgrp)
-		kargs->kill_seq = kargs->cgrp->kill_seq;
-	else
-		kargs->kill_seq = cset->dfl_cgrp->kill_seq;
+	kargs->kill_seq = cset->dfl_cgrp->kill_seq;
 	spin_unlock_irq(&css_set_lock);
 
 	if (!(kargs->flags & CLONE_INTO_CGROUP)) {
@@ -6844,6 +6841,7 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
 
 	put_css_set(cset);
 	kargs->cgrp = dst_cgrp;
+	kargs->kill_seq = dst_cgrp->kill_seq;
 	return ret;
 
 err: