[patch] sys-apps-busybox-1.36.1-r4-disable-FEATURE_NON_POSIX.patch

0001-sys-apps-busybox-1.36.1-r4-disable-FEATURE_NON_POSIX.patch (text/plain), 14.48 KB, created by kfm on 2024-09-10 02:09:47 UTC

From 4a062ddafbb146fbd8be353612ba49139431fa80 Mon Sep 17 00:00:00 2001
From: Kerin Millar <[e-mail]>
Date: Mon, 9 Sep 2024 21:31:27 +0100
Subject: [PATCH] sys-apps/busybox-1.36.1-r4: disable FEATURE_NON_POSIX_CP

By default, busybox enables the FEATURE_NON_POSIX_CP option. As is
implied by its name, it results in some rather flagrant POSIX
violations. In particular, it causes for the destination file to be
unlinked in the case that it already exists, losing the mode, access
time, birth time and other attributes borne by the original inode.

$ touch file1 file2
$ chmod 600 file2
$ ls -li file1 file2
1529415 -rw-r--r-- 1 kerin users 0 2024-09-10 00:39 file1
1529416 -rw------- 1 kerin users 0 2024-09-10 00:39 file2
$ busybox cp file1 file2
$ ls -li file1 file2
1529415 -rw-r--r-- 1 kerin users 0 2024-09-10 00:39 file1
1529417 -rw-r--r-- 1 kerin users 0 2024-09-10 00:40 file2

Of course, this also means that symlinks end up being clobbered.

$ ln -s file2 file3
$ ls -li file2 file3
1529417 -rw-r--r-- 1 kerin users 0 2024-09-10 00:40 file2
1529418 lrwxrwxrwx 1 kerin users 5 2024-09-10 00:41 file3 -> file2
$ busybox cp file1 file3
1529417 -rw-r--r-- 1 kerin users 0 2024-09-10 00:40 file2
1529419 -rw-r--r-- 1 kerin users 0 2024-09-10 00:42 file3

The argument presented by the busybox authors is twofold. Firstly, that
the behaviour with respect to symlinks helps to protect against symlink
attacks. Secondly, that the behaviour with respect to device nodes
constitutes a security feature because it makes it more difficult to
accidentally copy data into a device node.

I find the position of the authors to be specious, given the drastic
divergence in behaviour from the specification. The fact of the matter
is that the utility is not supposed to behave in this way. Indeed, there
are plausible use cases for which the standard behaviour might not only
be expected, but required.

As for the matter of device nodes, there is nothing wrong with using
cp(1) to write data to a file that happens to be a device node or a
symlink to one. The authors suggest to use cat(1) with redirection as
an alternative. Quite how the use of cat(1) is supposed to concretely
establish an intent to write to a block device is left as an exercise
for the reader.

As such, disable the feature so as to better conform to the
specification.

Signed-off-by: Kerin Millar <[e-mail]>
---
 sys-apps/busybox/busybox-1.36.1-r4.ebuild | 393 ++++++++++++++++++++++
 sys-apps/busybox/busybox-9999.ebuild      |   3 +
 2 files changed, 396 insertions(+)
 create mode 100644 sys-apps/busybox/busybox-1.36.1-r4.ebuild

diff --git a/sys-apps/busybox/busybox-1.36.1-r4.ebuild b/sys-apps/busybox/busybox-1.36.1-r4.ebuild
new file mode 100644
index 0000000000..07c6e9bb67
--- /dev/null
+++ b/sys-apps/busybox/busybox-1.36.1-r4.ebuild
@@ -0,0 +1,393 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# See `man savedconfig.eclass` for info on how to use USE=savedconfig.
+
+EAPI=8
+
+inherit flag-o-matic readme.gentoo-r1 savedconfig toolchain-funcs
+
+DESCRIPTION="Utilities for rescue and embedded systems"
+HOMEPAGE="https://www.busybox.net/"
+if [[ ${PV} == "9999" ]] ; then
+	MY_P="${P}"
+	EGIT_REPO_URI="https://git.busybox.net/busybox"
+	inherit git-r3
+else
+	MY_P="${PN}-${PV/_/-}"
+	SRC_URI="https://www.busybox.net/downloads/${MY_P}.tar.bz2"
+	KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux"
+fi
+S="${WORKDIR}/${MY_P}"
+
+LICENSE="GPL-2" # GPL-2 only
+SLOT="0"
+IUSE="debug livecd make-symlinks math mdev pam selinux sep-usr static syslog systemd"
+REQUIRED_USE="pam? ( !static )"
+RESTRICT="test"
+
+# TODO: Could make pkgconfig conditional on selinux? bug #782829
+RDEPEND="
+	!static? (
+		virtual/libc
+		virtual/libcrypt:=
+		selinux? ( sys-libs/libselinux )
+	)
+	pam? ( sys-libs/pam )
+"
+DEPEND="${RDEPEND}
+	static? (
+		virtual/libcrypt[static-libs]
+		selinux? ( sys-libs/libselinux[static-libs(+)] )
+	)
+	sys-kernel/linux-headers"
+BDEPEND="virtual/pkgconfig"
+
+DISABLE_AUTOFORMATTING=yes
+DOC_CONTENTS='
+If you want a smaller executable, add `-Oz` to your busybox `CFLAGS`.'
+
+busybox_config_option() {
+	local flag=$1 ; shift
+	if [[ ${flag} != [yn] && ${flag} != \"* ]] ; then
+		busybox_config_option $(usex ${flag} y n) "$@"
+		return
+	fi
+	local expr
+	while [[ $# -gt 0 ]] ; do
+		case ${flag} in
+		y) expr="s:.*\<CONFIG_$1\>.*set:CONFIG_$1=y:g" ;;
+		n) expr="s:CONFIG_$1=y:# CONFIG_$1 is not set:g" ;;
+		*) expr="s:.*\<CONFIG_$1\>.*:CONFIG_$1=${flag}:g" ;;
+		esac
+		sed -i -e "${expr}" .config || die
+		einfo "$(grep "CONFIG_$1[= ]" .config || echo "Could not find CONFIG_$1 ...")"
+		shift
+	done
+}
+
+busybox_config_enabled() {
+	local val=$(sed -n "/^CONFIG_$1=/s:^[^=]*=::p" .config)
+	case ${val} in
+	"") return 1 ;;
+	y)  return 0 ;;
+	*)  echo "${val}" | sed -r 's:^"(.*)"$:\1:' ;;
+	esac
+}
+
+# patches go here!
+PATCHES=(
+	"${FILESDIR}"/${PN}-1.26.2-bb.patch
+	"${FILESDIR}"/${PN}-1.34.1-skip-selinux-search.patch
+
+	"${FILESDIR}"/${PN}-1.36.0-fortify-source-3-fixdep.patch
+	"${FILESDIR}"/${PN}-1.36.1-kernel-6.8.patch
+
+	"${FILESDIR}"/${PN}-1.36.1-skip-dynamic-relocations.patch
+
+	# "${FILESDIR}"/${P}-*.patch
+)
+
+src_prepare() {
+	default
+
+	cp "${FILESDIR}"/ginit.c init/ || die
+
+	# flag cleanup
+	sed -i -r \
+		-e 's:[[:space:]]?-(Werror|Os|Oz|falign-(functions|jumps|loops|labels)=1|fomit-frame-pointer)\>::g' \
+		Makefile.flags || die
+	sed -i \
+		-e 's:-static-libgcc::' \
+		Makefile.flags || die
+
+	# Print all link lines too
+	sed -i -e 's:debug=false:debug=true:' scripts/trylink || die
+}
+
+bbmake() {
+	local args=(
+		V=1
+		CROSS_COMPILE="${CHOST}-"
+		AR="${AR}"
+		CC="${CC}"
+		HOSTCC="${BUILD_CC}"
+		HOSTCFLAGS="${BUILD_CFLAGS}"
+		PKG_CONFIG="${PKG_CONFIG}"
+	)
+	emake "${args[@]}" "$@"
+}
+
+src_configure() {
+	unset KBUILD_OUTPUT #88088
+	export SKIP_STRIP=y
+
+	tc-export AR CC BUILD_CC PKG_CONFIG
+
+	tc-is-cross-compiler || BUILD_CFLAGS=${CFLAGS}
+	BUILD_CFLAGS+=" -D_FILE_OFFSET_BITS=64" #930513
+
+	append-flags -fno-strict-aliasing #310413
+	use ppc64 && append-flags -mminimal-toc #130943
+
+	# check for a busybox config before making one of our own.
+	# if one exist lets return and use it.
+
+	restore_config .config
+	if [ -f .config ]; then
+		yes "" | bbmake -j1 oldconfig
+		return 0
+	else
+		ewarn "Could not locate user configfile, so we will save a default one"
+	fi
+
+	# setting SKIP_SELINUX skips searching for selinux at this stage. We don't
+	# need to search now in case we end up not needing it after all.
+	# setup the config file
+	bbmake -j1 allyesconfig SKIP_SELINUX=$(usex selinux n y) #620918
+	# nommu forces a bunch of things off which we want on #387555
+	busybox_config_option n NOMMU
+	sed -i '/^#/d' .config
+	yes "" | bbmake -j1 oldconfig SKIP_SELINUX=$(usex selinux n y) #620918
+
+	# now turn off stuff we really don't want
+	busybox_config_option n DMALLOC
+	busybox_config_option n FEATURE_2_4_MODULES #607548
+	busybox_config_option n FEATURE_SUID_CONFIG
+	busybox_config_option n BUILD_AT_ONCE
+	busybox_config_option n BUILD_LIBBUSYBOX
+	busybox_config_option n FEATURE_CLEAN_UP
+	busybox_config_option n MONOTONIC_SYSCALL
+	busybox_config_option n USE_PORTABLE_CODE
+	busybox_config_option n WERROR
+	# CONFIG_MODPROBE_SMALL=y disables depmod.c and uses a smaller one that
+	# does not support -b. Setting this to no creates slightly larger and
+	# slightly more useful modutils
+	busybox_config_option n MODPROBE_SMALL #472464
+	# triming the BSS size may be dangerous
+	busybox_config_option n FEATURE_USE_BSS_TAIL
+	# a conforming implementation of cp(1) will not create a new inode for
+	# cases such as `cp ./file ./existing-file`
+	busybox_config_option n FEATURE_NON_POSIX_CP
+
+	# These cause trouble with musl.
+	if use elibc_musl; then
+		busybox_config_option n FEATURE_UTMP
+		busybox_config_option n EXTRA_COMPAT
+		busybox_config_option n FEATURE_VI_REGEX_SEARCH
+	fi
+
+	# Disable standalone shell mode when using make-symlinks, else Busybox calls its
+	# applets by default without looking up in PATH.
+	# This also enables users to disable a builtin by deleting the corresponding symlink.
+	if use make-symlinks; then
+		busybox_config_option n FEATURE_PREFER_APPLETS
+		busybox_config_option n FEATURE_SH_STANDALONE
+	fi
+
+	# If these are not set and we are using a busybox setup
+	# all calls to system() will fail.
+	busybox_config_option y ASH
+	busybox_config_option y SH_IS_ASH
+	busybox_config_option n HUSH
+	busybox_config_option n SH_IS_HUSH
+
+	busybox_config_option '"/run"' PID_FILE_PATH
+	busybox_config_option '"/run/ifstate"' IFUPDOWN_IFSTATE_PATH
+
+	busybox_config_option pam PAM
+	busybox_config_option static STATIC
+	busybox_config_option syslog {K,SYS}LOGD LOGGER
+	busybox_config_option systemd FEATURE_SYSTEMD
+	busybox_config_option math FEATURE_AWK_LIBM
+
+	# all the debug options are compiler related, so punt them
+	busybox_config_option n DEBUG_SANITIZE
+	busybox_config_option n DEBUG
+	busybox_config_option y NO_DEBUG_LIB
+	busybox_config_option n DMALLOC
+	busybox_config_option n EFENCE
+	busybox_config_option $(usex debug y n) TFTP_DEBUG
+
+	busybox_config_option selinux SELINUX
+
+	# this opt only controls mounting with <linux-2.6.23
+	busybox_config_option n FEATURE_MOUNT_NFS
+
+	# glibc-2.26 and later does not ship RPC implientation
+	busybox_config_option n FEATURE_HAVE_RPC
+	busybox_config_option n FEATURE_INETD_RPC
+
+	# default a bunch of uncommon options to off
+	local opt
+	for opt in \
+		ADD_SHELL \
+		BEEP BOOTCHARTD \
+		CRONTAB \
+		DC DEVFSD DNSD DPKG{,_DEB} \
+		FAKEIDENTD FBSPLASH FOLD FSCK_MINIX FTP{GET,PUT} \
+		FEATURE_DEVFS \
+		HOSTID HUSH \
+		INETD INOTIFYD IPCALC \
+		LOCALE_SUPPORT LOGNAME LPD \
+		MAKEMIME MKFS_MINIX MSH \
+		OD \
+		RDEV READPROFILE REFORMIME REMOVE_SHELL RFKILL RUN_PARTS RUNSV{,DIR} \
+		SLATTACH SMEMCAP SULOGIN SV{,LOGD} \
+		TASKSET TCPSVD \
+		RPM RPM2CPIO \
+		UDPSVD UUDECODE UUENCODE
+	do
+		busybox_config_option n ${opt}
+	done
+
+	bbmake -j1 oldconfig
+}
+
+src_compile() {
+	bbmake busybox
+
+	# bug #701512
+	bbmake doc
+}
+
+src_install() {
+	unset KBUILD_OUTPUT #88088
+	save_config .config
+
+	into /
+	dodir /bin
+	if use sep-usr ; then
+		# install /ginit to take care of mounting stuff
+		exeinto /
+		newexe busybox_unstripped ginit
+		dosym /ginit /bin/bb
+		dosym bb /bin/busybox
+	else
+		newbin busybox_unstripped busybox
+		dosym busybox /bin/bb
+	fi
+	if use mdev ; then
+		dodir /$(get_libdir)/mdev/
+		use make-symlinks || dosym /bin/bb /sbin/mdev
+		cp "${S}"/examples/mdev_fat.conf "${ED}"/etc/mdev.conf || die
+		if [[ ! "$(get_libdir)" == "lib" ]]; then
+			#831251 - replace lib with lib64 where appropriate
+			sed -i -e "s:/lib/:/$(get_libdir)/:g" "${ED}"/etc/mdev.conf || die
+		fi
+
+		exeinto /$(get_libdir)/mdev/
+		doexe "${FILESDIR}"/mdev/*
+
+		newinitd "${FILESDIR}"/mdev.initd mdev
+	fi
+	if use livecd ; then
+		dosym busybox /bin/vi
+	fi
+
+	# add busybox daemon's, bug #444718
+	if busybox_config_enabled FEATURE_NTPD_SERVER; then
+		newconfd "${FILESDIR}"/ntpd.confd busybox-ntpd
+		newinitd "${FILESDIR}"/ntpd.initd busybox-ntpd
+	fi
+	if busybox_config_enabled SYSLOGD; then
+		newconfd "${FILESDIR}"/syslogd.confd busybox-syslogd
+		newinitd "${FILESDIR}"/syslogd.initd busybox-syslogd
+	fi
+	if busybox_config_enabled KLOGD; then
+		newconfd "${FILESDIR}"/klogd.confd busybox-klogd
+		newinitd "${FILESDIR}"/klogd.initd busybox-klogd
+	fi
+	if busybox_config_enabled WATCHDOG; then
+		newconfd "${FILESDIR}"/watchdog.confd busybox-watchdog
+		newinitd "${FILESDIR}"/watchdog.initd busybox-watchdog
+	fi
+	if busybox_config_enabled UDHCPC; then
+		sed -i 's:$((metric++)):$metric; metric=$((metric + 1)):' examples/udhcp/simple.script || die #801535
+		local path=$(busybox_config_enabled UDHCPC_DEFAULT_SCRIPT)
+		exeinto "${path%/*}"
+		newexe examples/udhcp/simple.script "${path##*/}"
+	fi
+	if busybox_config_enabled UDHCPD; then
+		insinto /etc
+		doins examples/udhcp/udhcpd.conf
+	fi
+	if busybox_config_enabled ASH && ! use make-symlinks; then
+		dosym -r /bin/busybox /bin/ash
+	fi
+	if busybox_config_enabled CROND; then
+		newconfd "${FILESDIR}"/crond.confd busybox-crond
+		newinitd "${FILESDIR}"/crond.initd busybox-crond
+	fi
+
+	# bundle up the symlink files for use later
+	bbmake DESTDIR="${ED}" install
+	# for compatibility, provide /usr/bin/env
+	mkdir -p _install/usr/bin || die
+	if [[ ! -e _install/usr/bin/env ]]; then
+		ln -s /bin/env _install/usr/bin/env || die
+	fi
+	rm _install/bin/busybox || die
+	tar cf busybox-links.tar -C _install . || : #;die
+	insinto /usr/share/${PN}
+	use make-symlinks && doins busybox-links.tar
+
+	dodoc AUTHORS README TODO
+
+	cd docs || die
+	doman busybox.1
+	docinto txt
+	dodoc *.txt
+	docinto pod
+	dodoc *.pod
+	docinto html
+	dodoc *.html
+
+	cd ../examples || die
+	docinto examples
+	dodoc inittab depmod.pl *.conf *.script undeb unrpm
+
+	cd ../networking || die
+	dodoc httpd_indexcgi.c httpd_post_upload.cgi
+
+	readme.gentoo_create_doc
+}
+
+pkg_preinst() {
+	if use make-symlinks ; then
+		mv "${ED}"/usr/share/${PN}/busybox-links.tar "${T}"/ || die
+	fi
+}
+
+pkg_postinst() {
+	savedconfig_pkg_postinst
+
+	if use make-symlinks ; then
+		cd "${T}" || die
+		mkdir _install
+		tar xf busybox-links.tar -C _install || die
+		# 907432: cp -n returns error if it skips any file, but that is expected here
+		# TODO: check if a new coreutils release has a replacement option
+		cp -nvpPR _install/* "${ROOT}"/
+	fi
+
+	if use sep-usr ; then
+		elog "In order to use the sep-usr support, you have to update your"
+		elog "kernel command line.  Add the option:"
+		elog "     init=/ginit"
+		elog "To launch a different init than /sbin/init, use:"
+		elog "     init=/ginit /sbin/yourinit"
+		elog "To get a rescue shell, you may boot with:"
+		elog "     init=/ginit bb"
+	fi
+
+	if [[ ${MERGE_TYPE} != binary ]] && ! is-flagq -Oz; then
+		for v in ${REPLACING_VERSIONS}; do
+			if ver_test ${v} -le 1.36.1; then
+				FORCE_PRINT_ELOG=yes
+			fi
+		done
+
+		readme.gentoo_print_elog
+	fi
+}
diff --git a/sys-apps/busybox/busybox-9999.ebuild b/sys-apps/busybox/busybox-9999.ebuild
index cd06d97bc0..42e8acc3f1 100644
--- a/sys-apps/busybox/busybox-9999.ebuild
+++ b/sys-apps/busybox/busybox-9999.ebuild
@@ -164,6 +164,9 @@ src_configure() {
 	busybox_config_option n MODPROBE_SMALL #472464
 	# triming the BSS size may be dangerous
 	busybox_config_option n FEATURE_USE_BSS_TAIL
+	# a conforming implementation of cp(1) will not create a new inode for
+	# cases such as `cp ./file ./existing-file`
+	busybox_config_option n FEATURE_NON_POSIX_CP
 
 	# These cause trouble with musl.
 	if use elibc_musl; then
-- 
2.45.2