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Summary

SELint is a program to perform static code analysis on SELinux policy source files.

Installing from tar download

To install from a downloaded tarball, first install the following dependencies:

On rpm based distros:

  • uthash-devel
  • libconfuse
  • libconfuse-devel
  • check
  • check-devel

On apt based distros:

  • uthash-dev
  • libconfuse-dev
  • check

Then run:

./configure
make
make install

Installing from git

If you are building from a git repo checkout, you'll also need bison, flex, autotools (automake, autoconf, aclocal, autoreconf) and the autoconf-archive package. Then you can run ./autogen.sh to set up autotools and then follow the steps above.

Usage

selint [OPTIONS] FILE [...]

Options

-c CONFIGFILE, --config=CONFIGFILE
	Override default config with config specified on command line.  See
	CONFIGURATION section for config file syntax.

--color=COLOR_OPTION
	Configure color output.  Options are on, off and auto (the default).

--context=CONTEXT_PATH
	Also parse any .te or .if files found in CONTEXT_PATH and load symbols
	associated with them for use when checking the policy files to be analyzed.
	No checks are run on these files. Implies -s.

--debug-parser
	Enable debug output for the internal policy parser.
	Very noisy, useful to debug parsing failures.

-d CHECKID, --disable=CHECKID
	Disable check with the given ID.

-e CHECKID, --enable=CHECKID
	Enable check with the given ID.

-E, --only-enabled
	Only run checks that are explicitly enabled with the --enable option.

-F, --fail
	Exit with a non-zero value if any issue was found.

-h, --help
	Show help menu about command line options.

-l LEVEL, --level=LEVEL
	Only list errors with a severity level at or greater than LEVEL.  Options
	are C (convention), S (style), W (warning), E (error), F (fatal error).  See
	SEVERITY LEVELS for more information.  If this option is not specified,
	SELint will default to the level selected in the applicable config file.

--scan-hidden-dirs
	Scan hidden directories.  By default hidden directories (like `.git`) are
	skipped in recursive mode.

-s, --source
	Run in "source mode" to scan a policy source repository that is designed to
	compile into a full system policy.  If this flag is not specified, SELint
	will assume that scanned policy files are intended to be loaded into the
	currently running system policy.

-S, --summary
	Display a summary of issues found after running the analysis.

--summary-only
	Only display a summary of issues found after running the analysis.
	Do not show the individual findings.  Implies -S.

-r, --recursive
	Scan recursively and check all SELinux policy files found.

-v, --verbose
	Enable verbose output

-V, --version
	Show version information and exit.

Configuration

A global configuration is specified at the install prefix supplied to ./configure (typically /usr/local/etc). This can be overridden on the command line using the -c option.

Options specified on the command line override options from the config file.

See the global config file for details on config file syntax.

Severity levels

SELint messages are assocatied with a severity level, indicating the significance of the issue. Available levels are listed below in increasing order of significance.

  • X (extra) - Miscellaneous checks, mainly for policy introspection. These must be explicitly enabled with their individual identifier.
  • C (convention) - A violation of common style conventions
  • S (style) - Stylistic "code smell" that may be associated with unintended behavior
  • W (warning) - Non standard policy that may result in issues such as run time errors or security issues
  • E (error) - Important issues that may result in errors at compile time or run time
  • F (fatal error) - Error that prevents further processing

SELint exceptions

To eliminate one or more checks on one line, add a comment containing a string in any of the following formats:

  • selint-disable:E-003
  • selint-disable: E-003
  • selint-disable:E-003,E-004
  • selint-disable: E-003, E-004

This is currently only supported in te and if files

Output

SELint outputs messages in the following format:

[filename]:[lineno]: ([SEVERITY LEVEL]): [MESSAGE] ([ISSUE ID])

For example:

example.te:127: (E) Interface from module not in optional_policy block (E-001)

Check IDs

The following checks may be performed:

Extra Checks:

  • X-001: Unused interface or template declaration
  • X-002: AV rule with excluded source or target (can affect policy binary size)

Convention Checks:

  • C-001: Violation of refpolicy te file ordering conventions
  • C-004: Interface does not have documentation comment
  • C-005: Permissions in av rule or class declaration not ordered
  • C-006: Declarations in require block not ordered
  • C-007: Redundant type specification instead of self keyword
  • C-008: Conditional expression identifier from foreign module

Style Checks:

  • S-001: Require block used instead of interface call
  • S-002: File context file labels with type not declared in module
  • S-003: Unnecessary semicolon
  • S-004: Template call from an interface
  • S-005: Declaration in interface
  • S-006: Bare module statement
  • S-007: Call to gen_context omits mls component
  • S-008: Unquoted gen_require block
  • S-009: Permission macro suffix does not match class name
  • S-010: Permission macro usage suggested
  • S-011: File context line containing only white spaces

Warning Checks:

  • W-001: Type, attribute or userspace class referenced without explicit declaration
  • W-002: Type, attribute, role or userspace class used but not listed in require block in interface
  • W-003: Unused type, attribute, role or userspace class listed in require block
  • W-004: Potentially unescaped regex character in file contexts paths
  • W-005: Interface call from module not in optional_policy block
  • W-006: Interface call with empty argument
  • W-007: Unquoted space in argument of interface call
  • W-008: Allow rule with complement or wildcard permission
  • W-009: Module name does not match file name
  • W-010: Call to unknown interface
  • W-011: Declaration in require block not defined in own module
  • W-012: Conditional expression contains unknown identifier
  • W-013: Incorrect usage of audit_access permission

Error Checks:

  • E-002: Bad file context format
  • E-003: Nonexistent user listed in fc file
  • E-004: Nonexistent role listed in fc file
  • E-005: Nonexistent type listed in fc file
  • E-006: Declaration and interface with same name
  • E-007: Usage of unknown permission or permission macro
  • E-008: Usage of unknown class
  • E-009: Empty optional or require macro block
  • E-010: Usage of unknown simple m4 macro or stray word

Fatal Error Checks:

  • F-001: Policy syntax error prevents further processing
  • F-002: Internal error in SELint

Reference policy conventions

To improve the accuracy and avoid false-positives SELint makes some assumptions about naming conventions and formatting of the policy:

  • Type identifiers should end with the suffix _t.
  • Role identifiers should end with the suffix _r.
  • Names of noop interfaces for availability checks should end with the suffix _stub.
  • Permission macros should end with the suffix _perms.
  • Class set macros should end with the suffix _class_set.
  • Security class declarations of userspace classes in the security_classes file should be declared with a comment including the word userspace.
  • Interfaces that wrap a file based type-transition should end with the suffix _filetrans.
  • Interfaces that transforms their arguments, e.g. associate an attribute with them, and thus should be handled like a declaration should have one of the following common suffixes: _type, _file, _domain, _node, _agent, _delivery, _sender, _boolean, _content, _constrained, _executable, _exemption, _object or _mountpoint.