| 1 | //go:build unix |
| 2 | |
| 3 | package host |
| 4 | |
| 5 | import ( |
| 6 | "errors" |
| 7 | "os" |
| 8 | "path/filepath" |
| 9 | "testing" |
| 10 | ) |
| 11 | |
| 12 | // Root chowns the registry files in the service user's /data. A planted |
| 13 | // symlink or hard link must be refused, never followed, so it cannot hand a |
| 14 | // root-owned file to the service user. |
| 15 | func TestOwnRegistryFileRefusesPlantedLinks(t *testing.T) { |
| 16 | dir := t.TempDir() |
| 17 | uid, gid := os.Getuid(), os.Getgid() |
| 18 | victim := filepath.Join(dir, "victim") |
| 19 | if err := os.WriteFile(victim, []byte("root's"), 0600); err != nil { |
| 20 | t.Fatal(err) |
| 21 | } |
| 22 | link := filepath.Join(dir, "registry.db-wal") |
| 23 | if err := os.Symlink(victim, link); err != nil { |
| 24 | t.Fatal(err) |
| 25 | } |
| 26 | if _, err := ownRegistryFile(link, uid, gid); !errors.Is(err, errRegistryFileShape) { |
| 27 | t.Fatalf("symlink followed or wrongly accepted: %v", err) |
| 28 | } |
| 29 | hard := filepath.Join(dir, "registry.db-shm") |
| 30 | if err := os.Link(victim, hard); err != nil { |
| 31 | t.Fatal(err) |
| 32 | } |
| 33 | if _, err := ownRegistryFile(hard, uid, gid); !errors.Is(err, errRegistryFileShape) { |
| 34 | t.Fatalf("hard link accepted: %v", err) |
| 35 | } |
| 36 | sub := filepath.Join(dir, "registry.db") |
| 37 | if err := os.Mkdir(sub, 0700); err != nil { |
| 38 | t.Fatal(err) |
| 39 | } |
| 40 | if _, err := ownRegistryFile(sub, uid, gid); !errors.Is(err, errRegistryFileShape) { |
| 41 | t.Fatalf("directory accepted: %v", err) |
| 42 | } |
| 43 | if _, err := ownRegistryFile(filepath.Join(dir, "absent"), uid, gid); !errors.Is(err, os.ErrNotExist) { |
| 44 | t.Fatalf("missing file: %v", err) |
| 45 | } |
| 46 | plain := filepath.Join(dir, "plain.db") |
| 47 | if err := os.WriteFile(plain, nil, 0600); err != nil { |
| 48 | t.Fatal(err) |
| 49 | } |
| 50 | if changed, err := ownRegistryFile(plain, uid, gid); err != nil || changed { |
| 51 | t.Fatalf("plain file already owned: changed=%v err=%v", changed, err) |
| 52 | } |
| 53 | } |
| 54 | |
amadan