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-rw-r--r--kernel/cgroup.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 15dcae74b510..5606c0f08d95 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2995,6 +2995,8 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
kernfs_type(kn) != KERNFS_DIR)
return -EINVAL;
+ mutex_lock(&cgroup_mutex);
+
/*
* We aren't being called from kernfs and there's no guarantee on
* @kn->priv's validity. For this and css_tryget_from_dir(),
@@ -3002,10 +3004,12 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
*/
rcu_read_lock();
cgrp = rcu_dereference(kn->priv);
- if (!cgrp) {
+ if (!cgrp || cgroup_is_dead(cgrp)) {
rcu_read_unlock();
+ mutex_unlock(&cgroup_mutex);
return -ENOENT;
}
+ rcu_read_unlock();
css_task_iter_start(&cgrp->dummy_css, &it);
while ((tsk = css_task_iter_next(&it))) {
@@ -3030,7 +3034,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
}
css_task_iter_end(&it);
- rcu_read_unlock();
+ mutex_unlock(&cgroup_mutex);
return 0;
}