System executables that are not owned by root pose a security risk. The owner of the executable is free to modify it at any time; so, for example, he can change a daemon's behavior to make it malicious before the next time the service is started (usually by root).
On a "normal" system, there is no good reason why the superuser should not own every system executable. This commit adds a new install-time check that reports any such binaries with a QA warning. To avoid false positives, non-"normal" systems (like prefix) are skipped at the moment. Bug: https://bugs.gentoo.org/629398 --- bin/install-qa-check.d/90bad-bin-owner | 38 ++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 bin/install-qa-check.d/90bad-bin-owner diff --git a/bin/install-qa-check.d/90bad-bin-owner b/bin/install-qa-check.d/90bad-bin-owner new file mode 100644 index 000000000..188d67a51 --- /dev/null +++ b/bin/install-qa-check.d/90bad-bin-owner @@ -0,0 +1,38 @@ +# Copyright 1999-2018 Gentoo Foundation +# Distributed under the terms of the GNU General Public License v2 + +bad_bin_owner_check() { + # Warn about globally-installed executables (in /bin, /usr/bin, /sbin, + # or /usr/sbin) that are owned by a nonzero UID. + + # This check doesn't work on non-root prefix installations at + # the moment, because every executable therein is owned by a + # nonzero UID. + [[ "${EUID}" -ne "0" || "${PORTAGE_INST_UID}" -ne "0" ]] && return + + local d f found=() + + for d in "${ED%/}/bin" "${ED%/}/usr/bin" "${ED%/}/sbin" "${ED%/}/usr/sbin"; do + [[ -d "${d}" ]] || continue + + # Read the results of the "find" command into the "found" bash array. + # Use -L to catch symlinks whose targets are owned by a non-root user, + # even though it won't catch ABSOLUTE symlinks until the package + # is RE-installed (the first time around, the target won't exist). + while read -r -d '' f; do + found+=( "${f}" ) + done < <(find -L "${d}" -maxdepth 1 -type f ! -uid 0 -print0) + + if [[ ${found[@]} ]]; then + eqawarn "system executables owned by nonzero uid:" + for f in "${found[@]}"; do + # Strip off the leading destdir before outputting the path, + # but leave the prefix if there is one. + eqawarn " ${f#${D%/}/}" + done + fi + done +} + +bad_bin_owner_check +: -- 2.16.4
