sys-apps/less: fix LESSOPEN escape vulnerability

Special thanks to the less upstream maintainer, Mark Nudelman, for providing
us with a backport to 643.

Bug: https://bugs.gentoo.org/929210
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 158 insertions, 0 deletions

diff --git a/sys-apps/less/files/less-643-LESSOPEN-escape.patch b/sys-apps/less/files/less-643-LESSOPEN-escape.patch
new file mode 100644
index 000000000000..f3fe50fcfaa2
--- /dev/null
+++ b/sys-apps/less/files/less-643-LESSOPEN-escape.patch
@@ -0,0 +1,61 @@
+https://openwall.com/lists/oss-security/2024/04/12/5
+https://bugs.gentoo.org/929210
+https://github.com/gwsw/less/commit/007521ac3c95bc76e3d59c6dbfe75d06c8075c33
+
+Upstream provided this version via email as a backport to 643.
+--- a/filename.c
++++ b/filename.c
+@@ -134,6 +134,15 @@
+ }
+ 
+ /*
++ * Must use quotes rather than escape char for this metachar?
++ */
++static int must_quote(char c)
++{
++	/* {{ Maybe the set of must_quote chars should be configurable? }} */
++	return (c == '\n'); 
++}
++
++/*
+  * Insert a backslash before each metacharacter in a string.
+  */
+ public char * shell_quote(char *s)
+@@ -164,6 +173,9 @@
+ 				 * doesn't support escape chars.  Use quotes.
+ 				 */
+ 				use_quotes = 1;
++			} else if (must_quote(*p))
++			{
++				len += 3; /* open quote + char + close quote */
+ 			} else
+ 			{
+ 				/*
+@@ -193,15 +205,22 @@
+ 	{
+ 		while (*s != '\0')
+ 		{
+-			if (metachar(*s))
++			if (!metachar(*s))
+ 			{
+-				/*
+-				 * Add the escape char.
+-				 */
++				*p++ = *s++;
++			} else if (must_quote(*s))
++			{
++				/* Surround the char with quotes. */
++				*p++ = openquote;
++				*p++ = *s++;
++				*p++ = closequote;
++			} else
++			{
++				/* Insert an escape char before the char. */
+ 				strcpy(p, esc);
+ 				p += esclen;
++				*p++ = *s++;
+ 			}
+-			*p++ = *s++;
+ 		}
+ 		*p = '\0';
+ 	}
diff --git a/sys-apps/less/less-643-r2.ebuild b/sys-apps/less/less-643-r2.ebuild
new file mode 100644
index 000000000000..a8159dc3fa9f
--- /dev/null
+++ b/sys-apps/less/less-643-r2.ebuild
@@ -0,0 +1,97 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Releases are usually first a beta then promoted to stable if no
+# issues were found. Upstream explicitly ask "to not generally distribute"
+# the beta versions. It's okay to keyword beta versions if they fix
+# a serious bug, but otherwise try to avoid it.
+
+WANT_AUTOMAKE=none
+WANT_LIBTOOL=none
+inherit autotools flag-o-matic optfeature toolchain-funcs
+
+DESCRIPTION="Excellent text file viewer"
+HOMEPAGE="https://www.greenwoodsoftware.com/less/"
+
+MY_PV=${PV/_beta/-beta}
+MY_P=${PN}-${MY_PV}
+
+if [[ ${PV} == 9999 ]]; then
+	EGIT_REPO_URI="https://github.com/gwsw/less"
+	inherit git-r3
+else
+	SRC_URI="https://www.greenwoodsoftware.com/less/${MY_P}.tar.gz"
+
+	if [[ ${PV} != *_beta* ]] ; then
+		KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
+	fi
+fi
+
+S="${WORKDIR}"/${MY_P/?beta}
+
+LICENSE="|| ( GPL-3 BSD-2 )"
+SLOT="0"
+IUSE="pcre test"
+# chinese1, utf8-2
+RESTRICT="test !test? ( test )"
+
+DEPEND="
+	>=app-misc/editor-wrapper-3
+	>=sys-libs/ncurses-5.2:=
+	pcre? ( dev-libs/libpcre2 )
+"
+RDEPEND="${DEPEND}"
+BDEPEND="test? ( virtual/pkgconfig )"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-643-lesstest-pkg-config.patch
+	"${FILESDIR}"/${PN}-643-LESSOPEN-escape.patch
+)
+
+src_prepare() {
+	default
+	# Per upstream README to prepare live build
+	[[ ${PV} == 9999 ]] && emake -f Makefile.aut distfiles
+	# Upstream uses unpatched autoconf-2.69, which breaks with clang-16.
+	# https://bugs.gentoo.org/870412
+	eautoreconf
+}
+
+src_configure() {
+	append-lfs-flags # bug #896316
+
+	local myeconfargs=(
+		--with-regex=$(usex pcre pcre2 posix)
+		--with-editor="${EPREFIX}"/usr/libexec/editor
+	)
+	econf "${myeconfargs[@]}"
+}
+
+src_test() {
+	emake check VERBOSE=1 CC="$(tc-getCC)" PKG_CONFIG="$(tc-getPKG_CONFIG)"
+}
+
+src_install() {
+	default
+
+	keepdir /usr/lib/lessfilter.d
+	keepdir /etc/lessfilter.d
+
+	newbin "${FILESDIR}"/lesspipe-r3.sh lesspipe
+	newenvd "${FILESDIR}"/less.envd 70less
+}
+
+pkg_preinst() {
+	optfeature "Colorized output support" dev-python/pygments
+
+	if has_version "<${CATEGORY}/${PN}-483-r1" ; then
+		elog "The lesspipe.sh symlink has been dropped.  If you are still setting"
+		elog "LESSOPEN to that, you will need to update it to '|lesspipe %s'."
+	fi
+
+	if has_version "<${CATEGORY}/${PN}-643" ; then
+		elog "less now colorizes by default. To disable this, set LESSCOLOR=no."
+	fi
+}