| 1 | //go:build linux |
| 2 | |
| 3 | package sandbox |
| 4 | |
| 5 | import ( |
| 6 | "os" |
| 7 | "path/filepath" |
| 8 | "reflect" |
| 9 | "slices" |
| 10 | "testing" |
| 11 | ) |
| 12 | |
| 13 | func TestLinuxWriteDirsSkipsMissingDirs(t *testing.T) { |
| 14 | home := t.TempDir() |
| 15 | t.Setenv("HOME", home) |
| 16 | if err := os.Mkdir(filepath.Join(home, ".cache"), 0o755); err != nil { |
| 17 | t.Fatal(err) |
| 18 | } |
| 19 | |
| 20 | got := linuxWriteDirs() |
| 21 | if !containsPath(got, filepath.Join(home, ".cache")) { |
| 22 | t.Fatalf("existing cache dir missing from linux write dirs: %v", got) |
| 23 | } |
| 24 | for _, missing := range []string{".cargo", ".npm", "go"} { |
| 25 | if containsPath(got, filepath.Join(home, missing)) { |
| 26 | t.Fatalf("missing dir %s should not be bound: %v", missing, got) |
| 27 | } |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | func TestBwrapExecutableMountArgsRevealsOnlyExactTemporaryExecutable(t *testing.T) { |
| 32 | got := bwrapExecutableMountArgs([]string{"/tmp/go-build123/b456/plugin.test", "-test.run=Helper"}) |
| 33 | want := []string{ |
| 34 | "--dir", "/tmp/go-build123", |
| 35 | "--dir", "/tmp/go-build123/b456", |
| 36 | "--ro-bind", "/tmp/go-build123/b456/plugin.test", "/tmp/go-build123/b456/plugin.test", |
| 37 | } |
| 38 | if !reflect.DeepEqual(got, want) { |
| 39 | t.Fatalf("temporary executable mount args = %v, want %v", got, want) |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | func TestBwrapExecutableMountArgsLeavesVisibleExecutableAlone(t *testing.T) { |
| 44 | if got := bwrapExecutableMountArgs([]string{"/usr/bin/node", "server.js"}); got != nil { |
| 45 | t.Fatalf("visible executable mount args = %v, want nil", got) |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | func TestBwrapArgsForArgsMountsTemporaryExecutableAfterMasks(t *testing.T) { |
| 50 | secretDir := t.TempDir() |
| 51 | argv := bwrapArgsForArgs(Spec{ |
| 52 | ForbidReadRoots: []string{secretDir}, |
| 53 | }, []string{"/tmp/go-build123/b456/plugin.test", "-test.run=Helper"}) |
| 54 | mask := indexArgs(argv, "--tmpfs", secretDir) |
| 55 | mount := indexArgs(argv, "--ro-bind", "/tmp/go-build123/b456/plugin.test", "/tmp/go-build123/b456/plugin.test") |
| 56 | if mask < 0 || mount < 0 || mount < mask { |
| 57 | t.Fatalf("temporary executable must be mounted after masks: %v", argv) |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | func TestBwrapProtectedWriteArgsRemountsReadonly(t *testing.T) { |
| 62 | home := t.TempDir() |
| 63 | state := filepath.Join(home, ".reasonix") |
| 64 | sessions := filepath.Join(state, "sessions") |
| 65 | if err := os.MkdirAll(sessions, 0o755); err != nil { |
| 66 | t.Fatal(err) |
| 67 | } |
| 68 | argv := bwrapBaseArgs(Spec{ |
| 69 | Mode: "enforce", |
| 70 | WriteRoots: []string{home}, |
| 71 | ProtectedWriteRoots: ProtectedWriteRoots(state), |
| 72 | MinimalWrites: true, |
| 73 | }) |
| 74 | homeBind := indexArgs(argv, "--bind", home, home) |
| 75 | protect := indexArgs(argv, "--ro-bind", state, state) |
| 76 | if homeBind < 0 || protect < 0 || protect < homeBind { |
| 77 | t.Fatalf("protected root must be remounted read-only after the home bind: %v", argv) |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | func TestBwrapProtectedWriteArgsReallowsOnlySafeStateChild(t *testing.T) { |
| 82 | state := t.TempDir() |
| 83 | skills := filepath.Join(state, "skills") |
| 84 | projects := filepath.Join(state, "projects", "slug") |
| 85 | if err := os.MkdirAll(skills, 0o755); err != nil { |
| 86 | t.Fatal(err) |
| 87 | } |
| 88 | if err := os.MkdirAll(projects, 0o755); err != nil { |
| 89 | t.Fatal(err) |
| 90 | } |
| 91 | argv := bwrapBaseArgs(Spec{ |
| 92 | Mode: "enforce", |
| 93 | WriteRoots: []string{skills, projects}, |
| 94 | ProtectedWriteRoots: ProtectedWriteRoots(state), |
| 95 | MinimalWrites: true, |
| 96 | }) |
| 97 | protect := indexArgs(argv, "--ro-bind", state, state) |
| 98 | if protect < 0 || indexArgs(argv[protect+1:], "--bind", skills, skills) < 0 { |
| 99 | t.Fatalf("safe state child must be reopened after parent protection: %v", argv) |
| 100 | } |
| 101 | if got := indexArgs(argv[protect+1:], "--bind", projects, projects); got >= 0 { |
| 102 | t.Fatalf("project runtime state must not be reopened: %v", argv) |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | func TestBwrapWriteRootUnderTmpReopensExactDirectory(t *testing.T) { |
| 107 | project, err := os.MkdirTemp("/tmp", "project-") |
| 108 | if err != nil { |
| 109 | t.Fatal(err) |
| 110 | } |
| 111 | t.Cleanup(func() { _ = os.RemoveAll(project) }) |
| 112 | root := filepath.Join(project, "cache") |
| 113 | if err := os.Mkdir(root, 0o755); err != nil { |
| 114 | t.Fatal(err) |
| 115 | } |
| 116 | argv := bwrapBaseArgs(Spec{ |
| 117 | Mode: "enforce", |
| 118 | WriteRoots: []string{root}, |
| 119 | SessionTemp: "/private/session-tmp", |
| 120 | MinimalWrites: true, |
| 121 | }) |
| 122 | tmpMount := indexArgs(argv, "--bind", "/private/session-tmp", "/tmp") |
| 123 | parent := indexArgs(argv, "--dir", project) |
| 124 | reopen := indexArgs(argv, "--bind", root, root) |
| 125 | if tmpMount < 0 || parent < tmpMount || reopen < parent { |
| 126 | t.Fatalf("temporary write root must be recreated after the private /tmp mount: %v", argv) |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | func TestBwrapProtectedWriteArgsIncludesMissingStateBoundary(t *testing.T) { |
| 131 | home := t.TempDir() |
| 132 | state := filepath.Join(home, "future-state") |
| 133 | argv := bwrapBaseArgs(Spec{ |
| 134 | Mode: "enforce", |
| 135 | WriteRoots: []string{home}, |
| 136 | ProtectedWriteRoots: ProtectedWriteRoots(state), |
| 137 | MinimalWrites: true, |
| 138 | }) |
| 139 | if indexArgs(argv, "--ro-bind", state, state) < 0 { |
| 140 | t.Fatalf("missing protected state must fail closed at launch: %v", argv) |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | func TestBwrapProtectedWriteArgsSkipsUnreachableStateBoundary(t *testing.T) { |
| 145 | state := filepath.Join(t.TempDir(), "future-state") |
| 146 | argv := bwrapBaseArgs(Spec{ |
| 147 | Mode: "enforce", |
| 148 | WriteRoots: []string{t.TempDir()}, |
| 149 | ProtectedWriteRoots: ProtectedWriteRoots(state), |
| 150 | MinimalWrites: true, |
| 151 | }) |
| 152 | if indexArgs(argv, "--ro-bind", state, state) >= 0 { |
| 153 | t.Fatalf("read-only filesystem already protects a disjoint state boundary: %v", argv) |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | func TestBwrapArgsBindsSessionTempAtTmp(t *testing.T) { |
| 158 | private := t.TempDir() |
| 159 | argv := bwrapArgs(Spec{ |
| 160 | Mode: "enforce", |
| 161 | SessionTemp: private, |
| 162 | WriteRoots: []string{t.TempDir()}, |
| 163 | }, Shell{Kind: ShellBash, Path: "bash"}, "true") |
| 164 | bind := indexArgs(argv, "--bind", private, "/tmp") |
| 165 | if bind < 0 { |
| 166 | t.Fatalf("expected --bind %s /tmp in %v", private, argv) |
| 167 | } |
| 168 | if indexArgs(argv, "--tmpfs", "/tmp") >= 0 { |
| 169 | t.Fatalf("session temp must not use tmpfs /tmp: %v", argv) |
| 170 | } |
| 171 | // Must not bind the host public temporary root as /tmp. |
| 172 | if host := os.TempDir(); host != private { |
| 173 | if indexArgs(argv, "--bind", host, "/tmp") >= 0 { |
| 174 | t.Fatalf("must not bind host temp %s at /tmp: %v", host, argv) |
| 175 | } |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | func TestBwrapArgsWithoutSessionTempKeepsTmpfs(t *testing.T) { |
| 180 | argv := bwrapArgs(Spec{Mode: "enforce"}, Shell{Kind: ShellBash, Path: "bash"}, "true") |
| 181 | if indexArgs(argv, "--tmpfs", "/tmp") < 0 { |
| 182 | t.Fatalf("independent sandbox should keep tmpfs /tmp: %v", argv) |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | func TestBwrapForbidReadArgsMasksFilesAndDirectories(t *testing.T) { |
| 187 | dir := t.TempDir() |
| 188 | nested := filepath.Join(dir, "nested") |
| 189 | if err := os.Mkdir(nested, 0o700); err != nil { |
| 190 | t.Fatal(err) |
| 191 | } |
| 192 | file := filepath.Join(t.TempDir(), "credentials.env") |
| 193 | if err := os.WriteFile(file, []byte("secret"), 0o600); err != nil { |
| 194 | t.Fatal(err) |
| 195 | } |
| 196 | missing := filepath.Join(dir, "missing") |
| 197 | |
| 198 | got := bwrapForbidReadArgs([]string{dir, nested, file, file, missing}) |
| 199 | want := []string{ |
| 200 | "--tmpfs", dir, |
| 201 | "--ro-bind", "/dev/null", file, |
| 202 | } |
| 203 | if !reflect.DeepEqual(got, want) { |
| 204 | t.Fatalf("forbid-read mount args = %v, want %v", got, want) |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | func indexArgs(args []string, want ...string) int { |
| 209 | for i := 0; i+len(want) <= len(args); i++ { |
| 210 | if reflect.DeepEqual(args[i:i+len(want)], want) { |
| 211 | return i |
| 212 | } |
| 213 | } |
| 214 | return -1 |
| 215 | } |
| 216 | |
| 217 | func containsPath(paths []string, want string) bool { |
| 218 | absWant, err := filepath.Abs(want) |
| 219 | if err != nil { |
| 220 | return false |
| 221 | } |
| 222 | return slices.Contains(paths, absWant) |
| 223 | } |
| 224 |