eba0ffee01
This is based on a patch by Nicolas Iooss. He writes:
When secilc compiles the following policy:
(block b1
(optional o1
(blockinherit b1)
(blockinherit x)
)
)
it disables the optional block at pass 3 (CIL_PASS_BLKIN_LINK)
because the block "x" does not exist.
__cil_resolve_ast_last_child_helper() calls
cil_tree_children_destroy() on the optional block, which destroys
the two blockinherit statements. But the (blockinherit b1) node
was referenced inside (block b1) node, in its block->bi_nodes list.
Therefore, when this list is used at pass 4 (CIL_PASS_BLKIN_COPY),
it contains a node which was freed: this triggers a use-after-free
issue
Fix this issue by removing blockinherit nodes from their lists of
nodes block->bi_nodes when they are being destroyed. As
cil_destroy_blockinherit() does not have a reference to the node
containing the blockinherit data, implement this new logic in
cil_tree_node_destroy().
This issue was found while investigating a testcase from an OSS-Fuzz
issue which seems unrelated (a Null-dereference READ in
cil_symtab_get_datum,
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=29861).
Reported-by: Nicolas Iooss <nicolas.iooss@m4x.org>
Signed-off-by: James Carter <jwcart2@gmail.com>
Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org>
|
||
|---|---|---|
| .circleci | ||
| .github/workflows | ||
| checkpolicy | ||
| dbus | ||
| gui | ||
| libselinux | ||
| libsemanage | ||
| libsepol | ||
| mcstrans | ||
| policycoreutils | ||
| python | ||
| restorecond | ||
| sandbox | ||
| scripts | ||
| secilc | ||
| semodule-utils | ||
| .gitignore | ||
| .travis.yml | ||
| CleanSpec.mk | ||
| CONTRIBUTING.md | ||
| lgtm.yml | ||
| Makefile | ||
| README.md | ||
| VERSION | ||
SELinux Userspace
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:
- Alpine Linux (https://pkgs.alpinelinux.org/package/edge/testing/x86/policycoreutils)
- Arch Linux User Repository (https://aur.archlinux.org/packages/policycoreutils/)
- Buildroot (https://git.buildroot.net/buildroot/tree/package/policycoreutils)
- Debian and Ubuntu (https://packages.debian.org/sid/policycoreutils)
- Gentoo (https://packages.gentoo.org/packages/sys-apps/policycoreutils)
- RHEL and Fedora (https://src.fedoraproject.org/rpms/policycoreutils)
- Yocto Project (http://git.yoctoproject.org/cgit/cgit.cgi/meta-selinux/tree/recipes-security/selinux)
- and many more (https://repology.org/project/policycoreutils/versions)
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