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James Carter 68573634b4 libsepol/cil: Improve in-statement to allow use after inheritance
CIL's in-statement is resolved before block inheritance. This has
the advantage of allowing an in-statement to add rules to a base
block (say for a new permission) and having those rules also be
added everywhere that base block is inherited. But the disadvantage
of this behavior is that it is not possible to use an in-statement
on a block that is inherited for the simple reason that that block
does not exist when the in-statment is resolved.

Change the syntax of the in-statement to allow specifying whether
the rules should be added before or after inheritance. If neither
is specified, then the behavior remains the same. All current
in-statements will work as before.

Either the old syntax
  (in container_id
      cil_statement
      ...
  )
or the new syntax
  (in before|after container_id
      cil_statement
      ...
  )
may be used for in-statements. But only "(in after ..." will have
the new behavior. Using "(in before ..." will give the same
behavior as before.

Macro Example
;
(block b1
  (macro m1 ((type ARG1))
    (allow ARG1 self (C1 (P1a)))
  )
)
(in after b1.m1
  (allow ARG1 self (C1 (P1c)))
)
(type t1a)
(call b1.m1 (t1a))
(blockinherit b1)
(in after m1
  (allow ARG1 self (C1 (P1b)))
)
(type t1b)
(call m1 (t1b))
;
This results in the following rules:
  (allow t1a self (C1 (P1a)))
  (allow t1a self (C1 (P1c)))
  (allow t1b self (C1 (P1a)))
  (allow t1b self (C1 (P1b)))

Block Example
;
(block b2
  (block b
    (type ta)
    (allow ta self (C2 (P2a)))
  )
)
(in before b2.b
  (type tb)
  (allow tb self (C2 (P2b)))
)
(block c2
  (blockinherit b2)
  (in after b
    (type tc)
    (allow tc self (C2 (P2c)))
  )
)
;
This results in the following rules:
  (allow b2.b.ta self (C2 (P2a)))
  (allow b2.b.tb self (C2 (P2b)))
  (allow c2.b.ta self (C2 (P2a)))
  (allow c2.b.tb self (C2 (P2b)))
  (allow c2.b.tc self (C2 (P2c)))

Using in-statements on optionals also works as expected.

One additional change is that blockabstract and blockinherit rules
are not allowed when using an after in-statement. This is because
both of those are resolved before an after in-statement would be
resolved.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-09-07 10:28:27 -04:00
.circleci CircleCI: run scan-build and publish its results automatically 2019-09-26 09:45:47 -04:00
.github/workflows ci: turn on CIFuzz 2021-07-13 21:03:29 +02:00
checkpolicy checkpolicy: mark read-only parameters in policy define const 2021-07-13 21:02:10 +02:00
dbus dbus: Use GLib.MainLoop() 2021-07-28 15:01:56 -04:00
gui Update VERSIONs to 3.2 for release. 2021-03-04 16:42:59 +01:00
libselinux Improve error message for label file validation 2021-08-23 10:30:10 -04:00
libsemanage libsemanage: Fix USE_AFTER_FREE (CWE-672) in semanage_direct_write_langext() 2021-07-28 14:23:54 -04:00
libsepol libsepol/cil: Improve in-statement to allow use after inheritance 2021-09-07 10:28:27 -04:00
mcstrans mcstrans: Improve mlstrans-test output 2021-08-10 12:25:14 -04:00
policycoreutils policycoreutils: free memory of allocated context in newrole 2021-07-19 10:42:45 -04:00
python python: Import specific modules from setools for less deps 2021-09-02 10:47:19 -04:00
restorecond Update VERSIONs to 3.2 for release. 2021-03-04 16:42:59 +01:00
sandbox Update VERSIONs to 3.2 for release. 2021-03-04 16:42:59 +01:00
scripts libsepol/cil: move the fuzz target and build script to the selinux repository 2021-08-17 10:33:47 -04:00
secilc secilc: fix memory leaks in secilc2conf 2021-07-19 10:42:45 -04:00
semodule-utils Update VERSIONs to 3.2 for release. 2021-03-04 16:42:59 +01:00
.gitignore restorecond: Add gitignore 2016-11-16 11:20:05 -05:00
.travis.yml travis: run only selinux-testsuite 2020-11-27 15:37:31 +01:00
CleanSpec.mk Add empty top level Android.mk / CleanSpec.mk files 2015-04-16 07:54:09 -04:00
CONTRIBUTING.md Fix many misspellings 2019-09-18 22:47:35 +02:00
lgtm.yml Add configuration file for lgtm.com 2019-09-18 08:24:11 -04:00
Makefile Makefile: always build with -fno-common 2020-01-27 10:51:23 -05:00
README.md README: add OSS-Fuzz/CIFuzz badges 2021-07-13 21:03:30 +02:00
VERSION Update VERSIONs to 3.2 for release. 2021-03-04 16:42:59 +01:00

SELinux Userspace

SELinux logo Build Status OSS-Fuzz Status CIFuzz Status

Please submit all bug reports and patches to selinux@vger.kernel.org.

Subscribe by sending "subscribe selinux" in the body of an email to majordomo@vger.kernel.org.

Archive of this mailing list is available on https://lore.kernel.org/selinux/.

Installation

SELinux libraries and tools are packaged in several Linux distributions:

Building and testing

Build dependencies on Fedora:

# For C libraries and programs
dnf install \
    audit-libs-devel \
    bison \
    bzip2-devel \
    CUnit-devel \
    diffutils \
    flex \
    gcc \
    gettext \
    glib2-devel \
    make \
    libcap-devel \
    libcap-ng-devel \
    pam-devel \
    pcre-devel \
    xmlto

# For Python and Ruby bindings
dnf install \
    python3-devel \
    ruby-devel \
    swig

Build dependencies on Debian:

# For C libraries and programs
apt-get install --no-install-recommends --no-install-suggests \
    bison \
    flex \
    gawk \
    gcc \
    gettext \
    make \
    libaudit-dev \
    libbz2-dev \
    libcap-dev \
    libcap-ng-dev \
    libcunit1-dev \
    libglib2.0-dev \
    libpcre3-dev \
    pkgconf \
    python3 \
    python3-distutils \
    systemd \
    xmlto

# For Python and Ruby bindings
apt-get install --no-install-recommends --no-install-suggests \
    python3-dev \
    ruby-dev \
    swig

To build and install everything under a private directory, run:

make clean distclean

make DESTDIR=~/obj install install-rubywrap install-pywrap

On Debian PYTHON_SETUP_ARGS=--install-layout=deb needs to be set when installing the python wrappers in order to create the correct python directory structure.

To run tests with the built libraries and programs, several paths (relative to $DESTDIR) need to be added to variables $LD_LIBRARY_PATH, $PATH and $PYTHONPATH. This can be done using ./scripts/env_use_destdir:

DESTDIR=~/obj ./scripts/env_use_destdir make test

Some tests require the reference policy to be installed (for example in python/sepolgen). In order to run these ones, instructions similar to the ones in section install of ./.travis.yml can be executed.

To install as the default system libraries and binaries (overwriting any previously installed ones - dangerous!), on x86_64, run:

make LIBDIR=/usr/lib64 SHLIBDIR=/lib64 install install-pywrap relabel

or on x86 (32-bit), run:

make install install-pywrap relabel

This may render your system unusable if the upstream SELinux userspace lacks library functions or other dependencies relied upon by your distribution. If it breaks, you get to keep both pieces.

Setting CFLAGS

Setting CFLAGS during the make process will cause the omission of many defaults. While the project strives to provide a reasonable set of default flags, custom CFLAGS could break the build, or have other undesired changes on the build output. Thus, be very careful when setting CFLAGS. CFLAGS that are encouraged to be set when overriding are:

  • -fno-semantic-interposition for gcc or compilers that do not do this. clang does this by default. clang-10 and up will support passing this flag, but ignore it. Previous clang versions fail.

macOS

To install libsepol on macOS (mainly for policy analysis):

cd libsepol; make PREFIX=/usr/local install

This requires GNU coreutils:

brew install coreutils