From 5f8890aa5b2814f1f554e84f4180efbd83f1fb6d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= Date: Thu, 5 Oct 2023 13:38:30 +0200 Subject: [PATCH] Set default SELinux labels on GnuPG directories Resolves: RHEL-6421 --- ...t-creation-SELinux-labels-on-GnuPG-d.patch | 335 ++++++++++++++++++ libdnf.spec | 17 +- 2 files changed, 349 insertions(+), 3 deletions(-) create mode 100644 0049-PGP-Set-a-default-creation-SELinux-labels-on-GnuPG-d.patch diff --git a/0049-PGP-Set-a-default-creation-SELinux-labels-on-GnuPG-d.patch b/0049-PGP-Set-a-default-creation-SELinux-labels-on-GnuPG-d.patch new file mode 100644 index 0000000..8c11b8b --- /dev/null +++ b/0049-PGP-Set-a-default-creation-SELinux-labels-on-GnuPG-d.patch @@ -0,0 +1,335 @@ +From 8752006f5f9c11bca3f04c99b463fd167caf0ddd Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= +Date: Wed, 4 Oct 2023 16:38:12 +0200 +Subject: [PATCH] PGP: Set a default creation SELinux labels on GnuPG + directories +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +libdnf used to precreate the directory in /run/user to make sure +a GnuPG agent executed by GPGME library places its socket there. + +The directories there are normally created and removed by systemd +(logind PAM session). libdnf created them for a case when a package +manager is invoked out of systemd session, before the super user logs +in. E.g. by a timer job to cache repository metadata. + +A problem was when this out-of-session process was a SELinux-confined +process creating files with its own SELinux label different from a DNF +program. Then the directory was created with a SELinux label different +from the one expected by systemd and when logging out a corresponding +user, the mismatching label clashed with systemd. + +The same issue was with temporary GnuPG home directories created by +libdnf under /tmp. + +This patch fixes both the isseus by restoring a SELinux label of those +directories to the label defined in a default SELinux file context +database. + +Obviously the database cannot have a record for a nonspecific +/tmp/tmpdir.XXXXXX (a mkdtemp() template) directory names. Therefore +I changed their names to more specific /tmp/libdnf.XXXXXX. Once +a SELinux policy updates the database, directories under /tmp will get +a correct label. + +There is yet another problem with accessing /var/cache/dnf/*/pubring, +but that seems to be pure SELinux policy problem. + +This patch adds a new -DENABLE_SELINUX=OFF CMake option to disable the +new dependency on libselinux. A default behavior is to support SELinux. + +Implementation details: + +I used selabel_lookup() + setfscreatecon() + mkdtemp() ++ setfscreatecon() sequence instead of mkdtemp() ++ selinux_restorecon() sequence because the later polutes stderr if +a SELinux policy does not define the default context. One could +supress stderr messages with selinux_set_callback(), but its effect +cannot be restored. + +I also kept the sequence in one function and reused it for creating +/run/user/$PID directories because the code is simpler than spliting +the function into three parts. + +https://issues.redhat.com/browse/RHEL-6421 +Signed-off-by: Petr Písař +--- + CMakeLists.txt | 7 +++ + libdnf.spec | 11 +++- + libdnf/CMakeLists.txt | 4 ++ + libdnf/repo/Repo.cpp | 121 +++++++++++++++++++++++++++++++++++++----- + 4 files changed, 129 insertions(+), 14 deletions(-) + +diff --git a/CMakeLists.txt b/CMakeLists.txt +index d895b2bf..e5829e6a 100644 +--- a/CMakeLists.txt ++++ b/CMakeLists.txt +@@ -34,6 +34,7 @@ option(WITH_MAN "Enables hawkey man page generation" ON) + option(WITH_ZCHUNK "Build with zchunk support" ON) + option(ENABLE_RHSM_SUPPORT "Build with Red Hat Subscription Manager support?" OFF) + option(ENABLE_SOLV_URPMREORDER "Build with support for URPM-like solution reordering?" OFF) ++option(ENABLE_SELINUX "Restore SELinux labels on GnuPG directories" ON) + + + # build options - debugging +@@ -83,6 +84,12 @@ if(ENABLE_RHSM_SUPPORT) + include_directories(${RHSM_INCLUDE_DIRS}) + endif() + ++if(ENABLE_SELINUX) ++ pkg_check_modules(SELINUX REQUIRED libselinux) ++ include_directories(${SELINUX_INCLUDE_DIRS}) ++ add_definitions(-DENABLE_SELINUX=1) ++endif() ++ + + # glibc: check if fnmatch.h has FNM_CASEFOLD symbol + include(CheckSymbolExists) +diff --git a/libdnf.spec b/libdnf.spec +index aa51dd28..df482f54 100644 +--- a/libdnf.spec ++++ b/libdnf.spec +@@ -42,6 +42,8 @@ + %bcond_with rhsm + %endif + ++%bcond_without selinux ++ + %if 0%{?rhel} + %bcond_with zchunk + %else +@@ -84,6 +86,9 @@ BuildRequires: pkgconfig(sqlite3) + BuildRequires: pkgconfig(json-c) + BuildRequires: pkgconfig(cppunit) + BuildRequires: pkgconfig(libcrypto) ++%if %{with selinux} ++BuildRequires: pkgconfig(libselinux) ++%endif + BuildRequires: pkgconfig(modulemd-2.0) >= %{libmodulemd_version} + BuildRequires: pkgconfig(smartcols) + BuildRequires: gettext +@@ -205,7 +210,8 @@ pushd build-py2 + %define __builddir build-py2 + %endif + %cmake -DPYTHON_DESIRED:FILEPATH=%{__python2} -DWITH_MAN=OFF ../ %{!?with_zchunk:-DWITH_ZCHUNK=OFF} %{!?with_valgrind:-DDISABLE_VALGRIND=1} %{_cmake_opts} -DLIBDNF_MAJOR_VERSION=%{libdnf_major_version} -DLIBDNF_MINOR_VERSION=%{libdnf_minor_version} -DLIBDNF_MICRO_VERSION=%{libdnf_micro_version} \ +- -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} ++ -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} \ ++ -DENABLE_SELINUX=%{?with_selinux:ON}%{!?with_selinux:OFF} + %make_build + popd + %endif +@@ -219,7 +225,8 @@ pushd build-py3 + %define __builddir build-py3 + %endif + %cmake -DPYTHON_DESIRED:FILEPATH=%{__python3} -DWITH_GIR=0 -DWITH_MAN=0 -Dgtkdoc=0 ../ %{!?with_zchunk:-DWITH_ZCHUNK=OFF} %{!?with_valgrind:-DDISABLE_VALGRIND=1} %{_cmake_opts} -DLIBDNF_MAJOR_VERSION=%{libdnf_major_version} -DLIBDNF_MINOR_VERSION=%{libdnf_minor_version} -DLIBDNF_MICRO_VERSION=%{libdnf_micro_version} \ +- -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} ++ -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} \ ++ -DENABLE_SELINUX=%{?with_selinux:ON}%{!?with_selinux:OFF} + %make_build + popd + %endif +diff --git a/libdnf/CMakeLists.txt b/libdnf/CMakeLists.txt +index 998a6f94..10b15230 100644 +--- a/libdnf/CMakeLists.txt ++++ b/libdnf/CMakeLists.txt +@@ -89,6 +89,10 @@ if(ENABLE_RHSM_SUPPORT) + target_link_libraries(libdnf ${RHSM_LIBRARIES}) + endif() + ++if(ENABLE_SELINUX) ++ target_link_libraries(libdnf ${SELINUX_LIBRARIES}) ++endif() ++ + set(DNF_SO_VERSION 2) + set_target_properties(libdnf PROPERTIES OUTPUT_NAME "dnf") + set_target_properties(libdnf PROPERTIES SOVERSION ${DNF_SO_VERSION}) +diff --git a/libdnf/repo/Repo.cpp b/libdnf/repo/Repo.cpp +index d61a24a5..68b82ccc 100644 +--- a/libdnf/repo/Repo.cpp ++++ b/libdnf/repo/Repo.cpp +@@ -51,6 +51,11 @@ + + #include + ++#if ENABLE_SELINUX ++#include ++#include ++#endif ++ + #include + #include + #include +@@ -649,6 +654,78 @@ std::unique_ptr Repo::Impl::lrHandleInitRemote(const char *destdir) + return h; + } + ++/* ++ * @brief Create a temporary directory. ++ * ++ * Creates a temporary directory with 0700 mode attempting to set a proper ++ * SELinux file context. Encountered errors are logged at debug level to ++ * a global logger. ++ * ++ * @param name_template As an input value it is a template according to ++ * mkdtemp(3). As an output value it will contain the created directory name. ++ * ++ * @return 0 if the directory was created, -1 if it wasn't. SELinux failures ++ * are not considered an error. ++ */ ++static int create_temporary_directory(char *name_template) { ++ auto logger(Log::getLogger()); ++ int retval = 0; ++#if ENABLE_SELINUX ++ char *old_default_context = NULL; ++ char *new_default_context = NULL; ++ int old_default_context_was_retrieved= 0; ++ struct selabel_handle *labeling_handle = NULL; ++ ++ /* A purpose of this piece of code is to deal with applications whose ++ * security policy overrides a file context for temporary files but don't ++ * know that libdnf executes GnuPG which expects a default file context. */ ++ if (0 == getfscreatecon(&old_default_context)) { ++ old_default_context_was_retrieved = 1; ++ } else { ++ logger->debug(tfm::format("Failed to retrieve a default SELinux context")); ++ } ++ ++ labeling_handle = selabel_open(SELABEL_CTX_FILE, NULL, 0); ++ if (NULL == labeling_handle) { ++ logger->debug(tfm::format("Failed to open a SELinux labeling handle: %s", ++ strerror(errno))); ++ } else { ++ if (selabel_lookup(labeling_handle, &new_default_context, name_template, 0700)) { ++ /* Here we could hard-code "system_u:object_r:user_tmp_t:s0", but ++ * that value should be really defined in default file context ++ * SELinux policy. Only log that the policy is incpomplete. */ ++ logger->debug(tfm::format("Failed to look up a default SELinux label for \"%s\"", ++ name_template)); ++ } else { ++ if (setfscreatecon(new_default_context)) { ++ logger->debug(tfm::format("Failed to set default SELinux context to \"%s\"", ++ new_default_context)); ++ } ++ freecon(new_default_context); ++ } ++ selabel_close(labeling_handle); ++ } ++#endif ++ ++ /* mkdtemp() assures 0700 mode. */ ++ if (NULL == mkdtemp(name_template)) { ++ logger->debug(tfm::format("Failed to create a directory \"%s\": %s", ++ name_template, strerror(errno))); ++ retval = -1; ++ } ++ ++#if ENABLE_SELINUX ++ if (old_default_context_was_retrieved) { ++ if (setfscreatecon(old_default_context)) { ++ logger->debug(tfm::format("Failed to restore a default SELinux context")); ++ } ++ } ++ freecon(old_default_context); ++#endif ++ ++ return retval; ++} ++ + static void gpgImportKey(gpgme_ctx_t context, int keyFd) + { + auto logger(Log::getLogger()); +@@ -703,8 +780,8 @@ static std::vector rawkey2infos(int fd) { + std::unique_ptr::type> context(ctx); + + // set GPG home dir +- char tmpdir[] = "/tmp/tmpdir.XXXXXX"; +- mkdtemp(tmpdir); ++ char tmpdir[] = "/tmp/libdnf.XXXXXX"; ++ create_temporary_directory(tmpdir); + Finalizer tmpDirRemover([&tmpdir](){ + dnf_remove_recursive(tmpdir, NULL); + }); +@@ -853,6 +930,13 @@ std::vector Repo::Impl::retrieve(const std::string & url) + * would cause a race condition with calling gpgme_release(), see [2], [3], + * [4]. + * ++ * Current solution precreating /run/user/$UID showed problematic when this ++ * library was used out of a systemd-logind session from a programm with an ++ * unexpected SELinux context. Then /run/user/$UID, normally maintained by ++ * systemd, was assigned a SELinux label unexpected by systemd causing errors ++ * on a user logout [5]. We remedy it by restoring the label according to ++ * a file context policy. ++ * + * Since the agent doesn't clean up its sockets properly, by creating this + * directory we make sure they are in a place that is not causing trouble with + * container images. +@@ -861,14 +945,27 @@ std::vector Repo::Impl::retrieve(const std::string & url) + * [2] https://bugzilla.redhat.com/show_bug.cgi?id=1769831 + * [3] https://github.com/rpm-software-management/microdnf/issues/50 + * [4] https://bugzilla.redhat.com/show_bug.cgi?id=1781601 ++ * [5] https://issues.redhat.com/browse/RHEL-6421 + */ + static void ensure_socket_dir_exists() { + auto logger(Log::getLogger()); ++ char tmpdir[] = "/run/user/libdnf.XXXXXX"; + std::string dirname = "/run/user/" + std::to_string(getuid()); +- int res = mkdir(dirname.c_str(), 0700); +- if (res != 0 && errno != EEXIST) { +- logger->debug(tfm::format("Failed to create directory \"%s\": %d - %s", +- dirname, errno, strerror(errno))); ++ ++ /* create_temporary_directory() assures 0700 mode and tries its best to ++ * correct a SELinux label. */ ++ if (create_temporary_directory(tmpdir)) { ++ return; ++ } ++ ++ /* Set the desired name. */ ++ if (rename(tmpdir, dirname.c_str())) { ++ if (errno != EEXIST && errno != ENOTEMPTY && errno != EBUSY) { ++ logger->debug(tfm::format("Failed to rename \"%s\" directory to \"%s\": %s", ++ tmpdir, dirname, strerror(errno))); ++ } ++ rmdir(tmpdir); ++ return; + } + } + +@@ -1151,8 +1248,8 @@ void Repo::Impl::addCountmeFlag(LrHandle *handle) { + bool Repo::Impl::isMetalinkInSync() + { + auto logger(Log::getLogger()); +- char tmpdir[] = "/tmp/tmpdir.XXXXXX"; +- mkdtemp(tmpdir); ++ char tmpdir[] = "/tmp/libdnf.XXXXXX"; ++ create_temporary_directory(tmpdir); + Finalizer tmpDirRemover([&tmpdir](){ + dnf_remove_recursive(tmpdir, NULL); + }); +@@ -1221,8 +1318,8 @@ bool Repo::Impl::isRepomdInSync() + { + auto logger(Log::getLogger()); + LrYumRepo *yum_repo; +- char tmpdir[] = "/tmp/tmpdir.XXXXXX"; +- mkdtemp(tmpdir); ++ char tmpdir[] = "/tmp/libdnf.XXXXXX"; ++ create_temporary_directory(tmpdir); + Finalizer tmpDirRemover([&tmpdir](){ + dnf_remove_recursive(tmpdir, NULL); + }); +@@ -1260,8 +1357,8 @@ void Repo::Impl::fetch(const std::string & destdir, std::unique_ptr && + throw RepoError(tfm::format(_("Cannot create repo destination directory \"%s\": %s"), + destdir, errTxt)); + } +- auto tmpdir = destdir + "/tmpdir.XXXXXX"; +- if (!mkdtemp(&tmpdir.front())) { ++ auto tmpdir = destdir + "/libdnf.XXXXXX"; ++ if (create_temporary_directory(&tmpdir.front())) { + const char * errTxt = strerror(errno); + throw RepoError(tfm::format(_("Cannot create repo temporary directory \"%s\": %s"), + tmpdir.c_str(), errTxt)); +-- +2.41.0 + diff --git a/libdnf.spec b/libdnf.spec index 3c9d0cc..1ff6026 100644 --- a/libdnf.spec +++ b/libdnf.spec @@ -42,6 +42,8 @@ %bcond_with rhsm %endif +%bcond_without selinux + %if 0%{?rhel} %bcond_with zchunk %else @@ -56,7 +58,7 @@ Name: libdnf Version: %{libdnf_major_version}.%{libdnf_minor_version}.%{libdnf_micro_version} -Release: 18%{?dist} +Release: 19%{?dist} Summary: Library providing simplified C and Python API to libsolv License: LGPLv2+ URL: https://github.com/rpm-software-management/libdnf @@ -109,6 +111,7 @@ Patch45: 0045-conf-Support-proxy-_none_-in-main-config-RhBug-21557.patch Patch46: 0046-Update-translations-RHEL-8.9.patch Patch47: 0047-filterAdvisory-installed_solvables-sort-RhBug2212838.patch Patch48: 0048-Avoid-reinstal-installonly-packages-marked-for-ERASE.patch +Patch49: 0049-PGP-Set-a-default-creation-SELinux-labels-on-GnuPG-d.patch BuildRequires: cmake @@ -133,6 +136,9 @@ BuildRequires: pkgconfig(sqlite3) BuildRequires: pkgconfig(json-c) BuildRequires: pkgconfig(cppunit) BuildRequires: pkgconfig(libcrypto) +%if %{with selinux} +BuildRequires: pkgconfig(libselinux) +%endif BuildRequires: pkgconfig(modulemd-2.0) >= %{libmodulemd_version} BuildRequires: pkgconfig(smartcols) BuildRequires: gettext @@ -254,7 +260,8 @@ pushd build-py2 %define __builddir build-py2 %endif %cmake -DPYTHON_DESIRED:FILEPATH=%{__python2} -DWITH_MAN=OFF ../ %{!?with_zchunk:-DWITH_ZCHUNK=OFF} %{!?with_valgrind:-DDISABLE_VALGRIND=1} %{_cmake_opts} -DLIBDNF_MAJOR_VERSION=%{libdnf_major_version} -DLIBDNF_MINOR_VERSION=%{libdnf_minor_version} -DLIBDNF_MICRO_VERSION=%{libdnf_micro_version} \ - -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} + -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} \ + -DENABLE_SELINUX=%{?with_selinux:ON}%{!?with_selinux:OFF} %make_build popd %endif @@ -268,7 +275,8 @@ pushd build-py3 %define __builddir build-py3 %endif %cmake -DPYTHON_DESIRED:FILEPATH=%{__python3} -DWITH_GIR=0 -DWITH_MAN=0 -Dgtkdoc=0 ../ %{!?with_zchunk:-DWITH_ZCHUNK=OFF} %{!?with_valgrind:-DDISABLE_VALGRIND=1} %{_cmake_opts} -DLIBDNF_MAJOR_VERSION=%{libdnf_major_version} -DLIBDNF_MINOR_VERSION=%{libdnf_minor_version} -DLIBDNF_MICRO_VERSION=%{libdnf_micro_version} \ - -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} + -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} \ + -DENABLE_SELINUX=%{?with_selinux:ON}%{!?with_selinux:OFF} %make_build popd %endif @@ -354,6 +362,9 @@ popd %endif %changelog +* Wed Oct 18 2023 Petr Pisar - 0.63.0-19 +- Set default SELinux labels on GnuPG directories (RHEL-6421) + * Fri Oct 13 2023 Jaroslav Rohel - 0.63.0-18 - filterAdvisory: match installed_solvables sort with lower_bound (RhBug:2212838, RHEL-1244) - Avoid reinstalling installonly packages marked for ERASE (RhBug:2163474, RHEL-1253)