mknod: /tmp/test_dev_cgroup_null: Operation not permitted 64+0 records in 64+0 records out 32768 bytes (33 kB, 32 KiB) copied, 0.000313491 s, 105 MB/s dd: failed to open '/dev/full': Operation not permitted dd: failed to open '/dev/random': Operation not permitted test_dev_cgroup:PASS :: [ PASS ] :: Test '8..41 selftests: bpf:test_dev_cgroup [PASS]'