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James Carter 71291385cf libsepol: Fix two problems with neverallowxperm reporting
Not all violations of neverallowxperm rules were being reported.
In check_assertion_extended_permissions_avtab(), a break was
performed after finding a match rather than just returning right
away. This means that if other src and tgt pairs were checked
afterward that did not match, then no match would be reported.

Example:
 allow attr attr:CLASS ioctl;
 allowxperm attr attr:CLASS ioctl 0x9401;
 allowxperm t1 self:CLASS ioctl 0x9421;
 neverallowxperm attr self:CLASS ioctl 0x9421;
Would result in no assertion violations being found.

Another problem was that the reporting function did not properly
recognize when there was a valid allowxperm rule and falsely
reported additional violations that did not exist. (There had
to be at least one legitimate violation.)

Using the same example as above (and assuming t1 and t2 both have
attribute attr), the following would be reported as:
  neverallowxperm on line 4 of policy.conf (or line 4 of policy.conf)
  violated by
  allowxperm t1 t1:CLASS ioctl { 0x9421 };

  neverallowxperm on line 4 of policy.conf (or line 4 of policy.conf)
  violated by
  allow t2 t2:CLASS4 { ioctl };

There is no violation for t2 because there is a valid allowxperm
rule for it.

With this patch, only the first error message (which is the correct
one) is printed.

Signed-off-by: James Carter <jwcart2@gmail.com>
2022-02-24 10:38:32 -05:00
.circleci Replace PCRE with PCRE2 build dependencies 2021-12-09 11:07:10 -05:00
.github/workflows ci: run the tests under ASan/UBsan on GHActions 2022-01-06 10:34:33 -05:00
checkpolicy checkpolicy: allow wildcard permissions in constraints 2022-02-18 14:48:57 -05:00
dbus Update VERSIONs to 3.3 for release. 2021-10-21 16:31:23 +02:00
gui Update VERSIONs to 3.3 for release. 2021-10-21 16:31:23 +02:00
libselinux libselinux: use PCRE2 by default 2021-12-09 11:07:00 -05:00
libsemanage libsemanage: optionally rebuild policy when modules are changed externally 2022-02-18 11:08:39 -05:00
libsepol libsepol: Fix two problems with neverallowxperm reporting 2022-02-24 10:38:32 -05:00
mcstrans mcstrans: port to new PCRE2 from end-of-life PCRE 2021-12-09 11:06:41 -05:00
policycoreutils semodule: add command-line option to detect module changes 2022-02-18 11:08:41 -05:00
python python: mark local functions static 2021-11-15 16:00:54 -05:00
restorecond Update VERSIONs to 3.3 for release. 2021-10-21 16:31:23 +02:00
sandbox sandbox: mark local functions static 2021-11-15 16:00:54 -05:00
scripts libsepol: add libfuzz based fuzzer for reading binary policies 2021-12-15 12:48:28 -05:00
secilc secilc/docs: Document the optional file type for genfscon rules 2021-12-09 10:46:26 -05:00
semodule-utils Update VERSIONs to 3.3 for release. 2021-10-21 16:31:23 +02:00
.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 Replace PCRE with PCRE2 build dependencies 2021-12-09 11:07:10 -05:00
lgtm.yml Add configuration file for lgtm.com 2019-09-18 08:24:11 -04:00
Makefile Enable extra global compiler warnings 2021-11-15 16:00:54 -05:00
README.md Replace PCRE with PCRE2 build dependencies 2021-12-09 11:07:10 -05:00
VERSION Update VERSIONs to 3.3 for release. 2021-10-21 16:31:23 +02:00

SELinux Userspace

SELinux logo Run Tests Run SELinux testsuite in a virtual machine 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 \
    pcre2-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 \
    libpcre2-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