From 34b491e735ad47c4805e63f3b83a659b8d10262b Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Wed, 9 Nov 2016 19:15:01 +0100 Subject: [PATCH] reset HOME, USER(NAME), TMPDIR & SHELL in DropPrivileges MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We can't cleanup the environment like e.g. sudo would do as you usually want the environment to "leak" into these helpers, but some variables like HOME should really not have still the value of the root user – it could confuse the helpers (USER) and HOME isn't accessible anyhow. Closes: 842877 --- apt-pkg/contrib/fileutl.cc | 20 ++++++++++++++++ debian/tests/run-tests | 2 +- test/integration/framework | 6 ++--- test/integration/skip-apt-dropprivs | 32 +++++++++++++++++++++++++ test/interactive-helper/CMakeLists.txt | 2 ++ test/interactive-helper/aptdropprivs.cc | 27 +++++++++++++++++++++ 6 files changed, 85 insertions(+), 4 deletions(-) create mode 100755 test/integration/skip-apt-dropprivs create mode 100644 test/interactive-helper/aptdropprivs.cc diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index 6c43bed90..d52e9b360 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -3051,6 +3051,26 @@ bool DropPrivileges() /*{{{*/ return _error->Error("Could restore a uid to root, privilege dropping did not work"); } + if (_config->FindB("APT::Sandbox::ResetEnvironment", true)) + { + setenv("HOME", pw->pw_dir, 1); + setenv("USER", pw->pw_name, 1); + setenv("USERNAME", pw->pw_name, 1); + setenv("LOGNAME", pw->pw_name, 1); + auto const shell = flNotDir(pw->pw_shell); + if (shell == "false" || shell == "nologin") + setenv("SHELL", "/bin/sh", 1); + else + setenv("SHELL", pw->pw_shell, 1); + auto const tmpdir = getenv("TMPDIR"); + if (tmpdir != nullptr) + { + auto const ourtmpdir = GetTempDir(); + if (ourtmpdir != tmpdir) + setenv("TMPDIR", ourtmpdir.c_str(), 1); + } + } + return true; } /*}}}*/ diff --git a/debian/tests/run-tests b/debian/tests/run-tests index 277594108..495f7edff 100644 --- a/debian/tests/run-tests +++ b/debian/tests/run-tests @@ -13,7 +13,7 @@ make -C build/test/interactive-helper # the host env does not pollute our environment env -i \ APT_INTEGRATION_TESTS_SOURCE_DIR=$(pwd) \ -APT_INTEGRATION_TESTS_WEBSERVER_BIN_DIR=$(pwd)/build/test/interactive-helper \ +APT_INTEGRATION_TESTS_HELPERS_BIN_DIR=$(pwd)/build/test/interactive-helper \ APT_INTEGRATION_TESTS_METHODS_DIR=/usr/lib/apt/methods \ APT_INTEGRATION_TESTS_LIBEXEC_DIR=/usr/lib/apt/ \ APT_INTEGRATION_TESTS_INTERNAL_SOLVER=/usr/lib/apt/solvers/apt \ diff --git a/test/integration/framework b/test/integration/framework index d5b68da84..03633f28a 100644 --- a/test/integration/framework +++ b/test/integration/framework @@ -190,7 +190,7 @@ aptmark() { runapt apt-mark "$@"; } aptsortpkgs() { runapt apt-sortpkgs "$@"; } apt() { runapt apt "$@"; } apthelper() { runapt "${APTHELPERBINDIR}/apt-helper" "$@"; } -aptwebserver() { runapt "${APTWEBSERVERBINDIR}/aptwebserver" "$@"; } +aptwebserver() { runapt "${APTTESTHELPERSBINDIR}/aptwebserver" "$@"; } aptitude() { runapt aptitude "$@"; } aptextracttemplates() { runapt apt-extracttemplates "$@"; } aptinternalsolver() { runapt "${APTINTERNALSOLVER}" "$@"; } @@ -331,7 +331,7 @@ setupenvironment() { LIBRARYPATH="${APT_INTEGRATION_TESTS_LIBRARY_PATH:-"${BUILDDIRECTORY}/../apt-pkg"}" METHODSDIR="${APT_INTEGRATION_TESTS_METHODS_DIR:-"${BUILDDIRECTORY}/../methods"}" APTHELPERBINDIR="${APT_INTEGRATION_TESTS_LIBEXEC_DIR:-"${BUILDDIRECTORY}"}" - APTWEBSERVERBINDIR="${APT_INTEGRATION_TESTS_WEBSERVER_BIN_DIR:-"${BUILDDIRECTORY}/../test/interactive-helper"}" + APTTESTHELPERSBINDIR="${APT_INTEGRATION_TESTS_HELPERS_BIN_DIR:-"${BUILDDIRECTORY}/../test/interactive-helper"}" APTFTPARCHIVEBINDIR="${APT_INTEGRATION_TESTS_FTPARCHIVE_BIN_DIR:-"${BUILDDIRECTORY}/../ftparchive"}" APTINTERNALSOLVER="${APT_INTEGRATION_TESTS_INTERNAL_SOLVER:-"${BUILDDIRECTORY}/solvers/apt"}" APTDUMPSOLVER="${APT_INTEGRATION_TESTS_DUMP_SOLVER:-"${BUILDDIRECTORY}/solvers/dump"}" @@ -1296,7 +1296,7 @@ changetowebserver() { else shift fi - if test -x "${APTWEBSERVERBINDIR}/aptwebserver"; then + if test -x "${APTTESTHELPERSBINDIR}/aptwebserver"; then cd aptarchive local LOG="webserver.log" if ! aptwebserver --port 0 -o aptwebserver::fork=1 -o aptwebserver::portfile='aptwebserver.port' "$@" >$LOG 2>&1 ; then diff --git a/test/integration/skip-apt-dropprivs b/test/integration/skip-apt-dropprivs new file mode 100755 index 000000000..e0dd741cd --- /dev/null +++ b/test/integration/skip-apt-dropprivs @@ -0,0 +1,32 @@ +#!/bin/sh +set -e + +TESTDIR="$(readlink -f "$(dirname "$0")")" +. "$TESTDIR/framework" + +setupenvironment +configarchitecture 'amd64' + +aptdropprivs() { runapt "${APTTESTHELPERSBINDIR}/aptdropprivs" "$@"; } + +testsuccess aptdropprivs -- /bin/true +testsuccess aptdropprivs --user "$USER" -- /bin/true +testsuccess aptdropprivs --user 'nobody' -- /bin/true +testsuccess aptdropprivs --user '_apt' -- /bin/true + +IDBIN='/usr/bin/id' +testsuccessequal "$("$IDBIN")" aptdropprivs --user "$USER" -- "$IDBIN" + +SUDOBIN='/usr/bin/sudo' +testequal "sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the 'nosuid' option set or an NFS file system without root privileges?" aptdropprivs --user 'nobody' -- "$SUDOBIN" "$IDBIN" + +if [ "$(id -u)" = '0' ]; then + testsuccessequal '_apt' aptdropprivs --user '_apt' -- "$IDBIN" '-un' + testsuccess aptdropprivs --user '_apt' -- '/bin/sh' '-c' 'export' + cp rootdir/tmp/testsuccess.output apt.env + testsuccessequal "export HOME='/nonexistent'" grep '^export HOME' apt.env + testsuccessequal "export USER='_apt' +export USERNAME='_apt'" grep '^export USER' apt.env + testsuccessequal "export LOGNAME='_apt'" grep '^export LOGNAME' apt.env + testsuccessequal "export SHELL='/bin/sh'" grep '^export SHELL=' apt.env +fi diff --git a/test/interactive-helper/CMakeLists.txt b/test/interactive-helper/CMakeLists.txt index 423fa30e6..5a32ca17e 100644 --- a/test/interactive-helper/CMakeLists.txt +++ b/test/interactive-helper/CMakeLists.txt @@ -6,6 +6,8 @@ add_executable(extract-control extract-control.cc) target_link_libraries(extract-control apt-pkg apt-inst) add_executable(aptwebserver aptwebserver.cc) target_link_libraries(aptwebserver apt-pkg ${CMAKE_THREAD_LIBS_INIT}) +add_executable(aptdropprivs aptdropprivs.cc) +target_link_libraries(aptdropprivs apt-pkg) add_executable(test_fileutl test_fileutl.cc) target_link_libraries(test_fileutl apt-pkg) diff --git a/test/interactive-helper/aptdropprivs.cc b/test/interactive-helper/aptdropprivs.cc new file mode 100644 index 000000000..1cc04f36a --- /dev/null +++ b/test/interactive-helper/aptdropprivs.cc @@ -0,0 +1,27 @@ +#include + +#include +#include +#include +#include + +#include + +int main(int const argc, const char * argv[]) +{ + CommandLine::Args Args[] = { + {'c',"config-file",0,CommandLine::ConfigFile}, + {'o',"option",0,CommandLine::ArbItem}, + {0, "user", "APT::Sandbox::User", CommandLine::HasArg}, + {0,0,0,0} + }; + + CommandLine CmdL(Args, _config); + if(CmdL.Parse(argc,argv) == false || DropPrivileges() == false) + { + _error->DumpErrors(std::cerr, GlobalError::DEBUG); + return 42; + } + + return execv(CmdL.FileList[0], const_cast(CmdL.FileList)); +} -- 2.45.2