Add worldwrite linter

pkg/build/linter.go

@@ -36,13 +36,14 @@ type linter struct {
 }
 
 var linterMap = map[string]linter{
- "dev": linter{devLinter, "If this package is creating /dev nodes, it should use udev instead; otherwise, remove any files in /dev"},
- "opt": linter{optLinter, "This package should be a -compat package"},
- "setuidgid": linter{isSetUidOrGidLinter, "Unset the setuid/setgid bit on the relevant files, or remove this linter"},
- "srv": linter{srvLinter, "This package should be a -compat package"},
- "tempdir": linter{tempDirLinter, "Remove any offending files in temporary dirs in the pipeline"},
- "usrlocal": linter{usrLocalLinter, "This package should be a -compat package"},
- "varempty": linter{varEmptyLinter, "Remove any offending files in /var/empty in the pipeline"},
+ "dev": linter{devLinter, "If this package is creating /dev nodes, it should use udev instead; otherwise, remove any files in /dev"},
+ "opt": linter{optLinter, "This package should be a -compat package"},
+ "setuidgid": linter{isSetUidOrGidLinter, "Unset the setuid/setgid bit on the relevant files, or remove this linter"},
+ "srv": linter{srvLinter, "This package should be a -compat package"},
+ "tempdir": linter{tempDirLinter, "Remove any offending files in temporary dirs in the pipeline"},
+ "usrlocal": linter{usrLocalLinter, "This package should be a -compat package"},
+ "varempty": linter{varEmptyLinter, "Remove any offending files in /var/empty in the pipeline"},
+ "worldwrite": linter{worldWriteableLinter, "Change the permissions of any world-writeable files in the package, disable the linter, or make this a -compat package"},
 }
 
 var isDevRegex = regexp.MustCompile("^dev/")
@@ -117,6 +118,29 @@ func varEmptyLinter(_ LinterContext, path string, _ fs.DirEntry) error {
  return nil
 }
 
+func worldWriteableLinter(_ LinterContext, path string, d fs.DirEntry) error {
+ if !d.Type().IsRegular() {
+ // Don't worry about non-files
+ return nil
+ }
+
+ info, err := d.Info()
+ if err != nil {
+ return err
+ }
+
+ mode := info.Mode()
+ if mode&0002 != 0 {
+ if mode&0111 != 0 {
+ return fmt.Errorf("World-writeable executable file found in package (security risk)")
+ } else {
+ return fmt.Errorf("World-writeable file found in package")
+ }
+ }
+
+ return nil
+}
+
 func lintPackageFs(lctx LinterContext, fsys fs.FS, linters []string) error {
  // If this is a compat package, do nothing.
  if isCompatPackage.MatchString(lctx.pkgname) {

pkg/build/linter_test.go

@@ -37,7 +37,7 @@ func Test_usrLocalLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"usrlocal"},
- Disabled: []string{"dev", "opt", "setuidgid", "srv", "tempdir", "varempty"},
+ Disabled: []string{"dev", "opt", "setuidgid", "srv", "tempdir", "varempty", "worldwrite"},
  },
  },
  }
@@ -66,7 +66,7 @@ func Test_varEmptyLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"varempty"},
- Disabled: []string{"dev", "opt", "setuidgid", "srv", "tempdir", "usrlocal"},
+ Disabled: []string{"dev", "opt", "setuidgid", "srv", "tempdir", "usrlocal", "worldwrite"},
  },
  },
  }
@@ -96,7 +96,7 @@ func Test_devLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"dev"},
- Disabled: []string{"opt", "setuidgid", "srv", "tempdir", "usrlocal", "varempty"},
+ Disabled: []string{"opt", "setuidgid", "srv", "tempdir", "usrlocal", "varempty", "worldwrite"},
  },
  },
  }
@@ -126,7 +126,7 @@ func Test_optLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"opt"},
- Disabled: []string{"dev", "setuidgid", "srv", "tempdir", "usrlocal", "varempty"},
+ Disabled: []string{"dev", "setuidgid", "srv", "tempdir", "usrlocal", "varempty", "worldwrite"},
  },
  },
  }
@@ -156,7 +156,7 @@ func Test_srvLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"srv"},
- Disabled: []string{"dev", "opt", "setuidgid", "tempdir", "usrlocal", "varempty"},
+ Disabled: []string{"dev", "opt", "setuidgid", "tempdir", "usrlocal", "varempty", "worldwrite"},
  },
  },
  }
@@ -186,7 +186,7 @@ func Test_tempDirLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"tempdir"},
- Disabled: []string{"dev", "opt", "setuidgid", "srv", "usrlocal", "varempty"},
+ Disabled: []string{"dev", "opt", "setuidgid", "srv", "usrlocal", "varempty", "worldwrite"},
  },
  },
  }
@@ -247,7 +247,7 @@ func Test_setUidGidLinter(t *testing.T) {
  Epoch: 0,
  Checks: config.Checks{
  Enabled: []string{"setuidgid"},
- Disabled: []string{"dev", "opt", "srv", "tempdir", "usrlocal", "varempty"},
+ Disabled: []string{"dev", "opt", "srv", "tempdir", "usrlocal", "varempty", "worldwrite"},
  },
  },
  }
@@ -271,6 +271,61 @@ func Test_setUidGidLinter(t *testing.T) {
  assert.Error(t, lintPackageFs(lctx, fsys, linters))
 }
 
+func Test_worldWriteLinter(t *testing.T) {
+ dir, err := os.MkdirTemp("", "melange.XXXXX")
+ defer os.RemoveAll(dir)
+ assert.NoError(t, err)
+
+ cfg := config.Configuration{
+ Package: config.Package{
+ Name: "test",
+ Version: "4.2.0",
+ Epoch: 0,
+ Checks: config.Checks{
+ Enabled: []string{"worldwrite"},
+ Disabled: []string{"dev", "opt", "srv", "setuidgid", "tempdir", "usrlocal", "varempty"},
+ },
+ },
+ }
+
+ usrLocalDirPath := filepath.Join(dir, "usr", "lib")
+ err = os.MkdirAll(usrLocalDirPath, 0777)
+ assert.NoError(t, err)
+
+ // Ensure 777 dirs don't trigger it
+ linters := cfg.Package.Checks.GetLinters()
+ assert.Equal(t, linters, []string{"worldwrite"})
+ fsys := os.DirFS(dir)
+ lctx := LinterContext{cfg.Package.Name, &cfg, &cfg.Package.Checks}
+ assert.NoError(t, lintPackageFs(lctx, fsys, linters))
+
+ // Create test file
+ filePath := filepath.Join(usrLocalDirPath, "test.txt")
+ _, err = os.Create(filepath.Join(filePath))
+ assert.NoError(t, err)
+
+ // Set writeable and executable bits for non-world
+ err = os.Chmod(filePath, 0770)
+ assert.NoError(t, err)
+
+ // Linter should not trigger
+ assert.NoError(t, lintPackageFs(lctx, fsys, linters))
+
+ // Set writeable bit (but not executable bit)
+ err = os.Chmod(filePath, 0776)
+ assert.NoError(t, err)
+
+ // Linter should trigger
+ assert.Error(t, lintPackageFs(lctx, fsys, linters))
+
+ // Set writeable and executable bit
+ err = os.Chmod(filePath, 0777)
+ assert.NoError(t, err)
+
+ // Linter should trigger
+ assert.Error(t, lintPackageFs(lctx, fsys, linters))
+}
+
 func Test_disableDefaultLinter(t *testing.T) {
  dir, err := os.MkdirTemp("", "melange.XXXXX")
  defer os.RemoveAll(dir)

pkg/config/config.go

@@ -345,6 +345,7 @@ var defaultLinters = []string{
  "tempdir",
  "usrlocal",
  "varempty",
+ "worldwrite",
 }
 
 type VarTransforms struct {