4 files changed, 23 insertions, 16 deletions

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 024085daab1a..a2c05d2476ac 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -123,7 +123,11 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 	 */
 	do {
 		css_task_iter_start(&from->self, 0, &it);
-		task = css_task_iter_next(&it);
+
+		do {
+			task = css_task_iter_next(&it);
+		} while (task && (task->flags & PF_EXITING));
+
 		if (task)
 			get_task_struct(task);
 		css_task_iter_end(&it);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 0b1ffe147f24..8cda3bc3ae22 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1397,7 +1397,7 @@ static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
 			 cgroup_on_dfl(cgrp) ? ss->name : ss->legacy_name,
 			 cft->name);
 	else
-		strncpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
+		strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
 	return buf;
 }
 
@@ -1864,9 +1864,9 @@ void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts)
 
 	root->flags = opts->flags;
 	if (opts->release_agent)
-		strcpy(root->release_agent_path, opts->release_agent);
+		strscpy(root->release_agent_path, opts->release_agent, PATH_MAX);
 	if (opts->name)
-		strcpy(root->name, opts->name);
+		strscpy(root->name, opts->name, MAX_CGROUP_ROOT_NAMELEN);
 	if (opts->cpuset_clone_children)
 		set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags);
 }
@@ -4125,26 +4125,24 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
 
 static void css_task_iter_advance(struct css_task_iter *it)
 {
-	struct list_head *l = it->task_pos;
+	struct list_head *next;
 
 	lockdep_assert_held(&css_set_lock);
-	WARN_ON_ONCE(!l);
-
 repeat:
 	/*
 	 * Advance iterator to find next entry.  cset->tasks is consumed
 	 * first and then ->mg_tasks.  After ->mg_tasks, we move onto the
 	 * next cset.
 	 */
-	l = l->next;
+	next = it->task_pos->next;
 
-	if (l == it->tasks_head)
-		l = it->mg_tasks_head->next;
+	if (next == it->tasks_head)
+		next = it->mg_tasks_head->next;
 
-	if (l == it->mg_tasks_head)
+	if (next == it->mg_tasks_head)
 		css_task_iter_advance_css_set(it);
 	else
-		it->task_pos = l;
+		it->task_pos = next;
 
 	/* if PROCS, skip over tasks which aren't group leaders */
 	if ((it->flags & CSS_TASK_ITER_PROCS) && it->task_pos &&
@@ -4449,6 +4447,7 @@ static struct cftype cgroup_base_files[] = {
 	},
 	{
 		.name = "cgroup.threads",
+		.flags = CFTYPE_NS_DELEGATABLE,
 		.release = cgroup_procs_release,
 		.seq_start = cgroup_threads_start,
 		.seq_next = cgroup_procs_next,
diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c
index 5f780d8f6a9d..9caeda610249 100644
--- a/kernel/cgroup/debug.c
+++ b/kernel/cgroup/debug.c
@@ -50,7 +50,7 @@ static int current_css_set_read(struct seq_file *seq, void *v)
 
 	spin_lock_irq(&css_set_lock);
 	rcu_read_lock();
-	cset = rcu_dereference(current->cgroups);
+	cset = task_css_set(current);
 	refcnt = refcount_read(&cset->refcount);
 	seq_printf(seq, "css_set %pK %d", cset, refcnt);
 	if (refcnt > cset->nr_tasks)
@@ -96,7 +96,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
 
 	spin_lock_irq(&css_set_lock);
 	rcu_read_lock();
-	cset = rcu_dereference(current->cgroups);
+	cset = task_css_set(current);
 	list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
 		struct cgroup *c = link->cgrp;
 
diff --git a/kernel/cgroup/stat.c b/kernel/cgroup/stat.c
index 133b465691d6..1e111dd455c4 100644
--- a/kernel/cgroup/stat.c
+++ b/kernel/cgroup/stat.c
@@ -296,8 +296,12 @@ int cgroup_stat_init(struct cgroup *cgrp)
 	}
 
 	/* ->updated_children list is self terminated */
-	for_each_possible_cpu(cpu)
-		cgroup_cpu_stat(cgrp, cpu)->updated_children = cgrp;
+	for_each_possible_cpu(cpu) {
+		struct cgroup_cpu_stat *cstat = cgroup_cpu_stat(cgrp, cpu);
+
+		cstat->updated_children = cgrp;
+		u64_stats_init(&cstat->sync);
+	}
 
 	prev_cputime_init(&cgrp->stat.prev_cputime);