Merge branch 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:
 "This is a high priority but low risk fix for a cgroup1 bug where
  rename(2) can change a cgroup's name to something which can break
  parsing of /proc/PID/cgroup"

* 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup1: don't allow '\n' in renaming

Author: torvalds

kernel/cgroup/cgroup-v1.c

@@ -820,6 +820,10 @@ static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent
 	struct cgroup *cgrp = kn->priv;
 	int ret;
 
+	/* do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable */
+	if (strchr(new_name_str, '\n'))
+		return -EINVAL;
+
 	if (kernfs_type(kn) != KERNFS_DIR)
 		return -ENOTDIR;
 	if (kn->parent != new_parent)