Re: [gentoo-portage-dev] [PATCH v3] ebuild-helpers: avoid exec loops or fork bombs in wrappers (bug 547086)

[Brian Dolbec <dolsen@gentoo.org>]

On Mon, 27 Apr 2015 18:53:02 -0700
Zac Medico <zmedico@gentoo.org> wrote:

> Since commit 130c01b9e561dd6ff7733a4905b21a0a921e9a22, extra portage
> paths in PATH could trigger exec loops or fork bombs in wrappers.
> 
> Fixes: 130c01b9e561 ("_doebuild_path: add fallback for temp
> PORTAGE_BIN_PATH (bug 547086)") X-Gentoo-Bug: 547086
> X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=547086
> ---
> [PATCH v3] fixes broken ${X} references
> 
>  bin/ebuild-helpers/bsd/sed            |  4 +++-
>  bin/ebuild-helpers/portageq           |  4 +++-
>  bin/ebuild-helpers/unprivileged/chown |  4 +++-
>  bin/ebuild-helpers/xattr/install      | 14 +++++++++++++-
>  4 files changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/bin/ebuild-helpers/bsd/sed b/bin/ebuild-helpers/bsd/sed
> index 01b8847..9a7f2d4 100755
> --- a/bin/ebuild-helpers/bsd/sed
> +++ b/bin/ebuild-helpers/bsd/sed
> @@ -1,5 +1,5 @@
>  #!/bin/bash
> -# Copyright 2007-2012 Gentoo Foundation
> +# Copyright 2007-2015 Gentoo Foundation
>  # Distributed under the terms of the GNU General Public License v2
>  
>  scriptpath=${BASH_SOURCE[0]}
> @@ -15,6 +15,8 @@ else
>  
>  	for path in $PATH; do
>  		if [[ -x ${path}/${scriptname} ]]; then
> +			[[ ${path} ==
> ${PORTAGE_OVERRIDE_EPREFIX}/usr/lib*/portage/* ]] && continue
> +			[[ ${path} == */._portage_reinstall_.* ]] &&
> continue [[ ${path}/${scriptname} -ef ${scriptpath} ]] && continue
>  			exec "${path}/${scriptname}" "$@"
>  			exit 0
> diff --git a/bin/ebuild-helpers/portageq b/bin/ebuild-helpers/portageq
> index 4151bac..ba889eb 100755
> --- a/bin/ebuild-helpers/portageq
> +++ b/bin/ebuild-helpers/portageq
> @@ -1,5 +1,5 @@
>  #!/bin/bash
> -# Copyright 2009-2013 Gentoo Foundation
> +# Copyright 2009-2015 Gentoo Foundation
>  # Distributed under the terms of the GNU General Public License v2
>  
>  scriptpath=${BASH_SOURCE[0]}
> @@ -15,6 +15,8 @@ set -f # in case ${PATH} contains any shell glob
> characters 
>  for path in ${PATH}; do
>  	[[ -x ${path}/${scriptname} ]] || continue
> +	[[ ${path} == ${PORTAGE_OVERRIDE_EPREFIX}/usr/lib*/portage/*
> ]] && continue
> +	[[ ${path} == */._portage_reinstall_.* ]] && continue
>  	[[ ${path}/${scriptname} -ef ${scriptpath} ]] && continue
>  	PYTHONPATH=${PORTAGE_PYTHONPATH:-${PORTAGE_PYM_PATH}} \
>  		exec "${PORTAGE_PYTHON:-/usr/bin/python}" \
> diff --git a/bin/ebuild-helpers/unprivileged/chown
> b/bin/ebuild-helpers/unprivileged/chown index 08fa650..2f1f161 100755
> --- a/bin/ebuild-helpers/unprivileged/chown
> +++ b/bin/ebuild-helpers/unprivileged/chown
> @@ -1,5 +1,5 @@
>  #!/bin/bash
> -# Copyright 2012-2013 Gentoo Foundation
> +# Copyright 2012-2015 Gentoo Foundation
>  # Distributed under the terms of the GNU General Public License v2
>  
>  scriptpath=${BASH_SOURCE[0]}
> @@ -9,6 +9,8 @@ IFS=':'
>  
>  for path in ${PATH}; do
>  	[[ -x ${path}/${scriptname} ]] || continue
> +	[[ ${path} == ${PORTAGE_OVERRIDE_EPREFIX}/usr/lib*/portage/*
> ]] && continue
> +	[[ ${path} == */._portage_reinstall_.* ]] && continue
>  	[[ ${path}/${scriptname} -ef ${scriptpath} ]] && continue
>  	IFS=$' \t\n'
>  	output=$("${path}/${scriptname}" "$@" 2>&1)
> diff --git a/bin/ebuild-helpers/xattr/install
> b/bin/ebuild-helpers/xattr/install index d572fe6..2d2a693 100755
> --- a/bin/ebuild-helpers/xattr/install
> +++ b/bin/ebuild-helpers/xattr/install
> @@ -1,5 +1,5 @@
>  #!/bin/bash
> -# Copyright 2013 Gentoo Foundation
> +# Copyright 2013-2015 Gentoo Foundation
>  # Distributed under the terms of the GNU General Public License v2
>  
>  PORTAGE_BIN_PATH=${PORTAGE_BIN_PATH:-/usr/lib/portage/bin}
> @@ -24,6 +24,18 @@ else
>  	fi
>  fi
>  
> +# Filter internal portage paths from PATH, in order to avoid
> +# a possible exec loop or fork bomb (see bug 547086).
> +IFS=':'
> +set -f
> +path=
> +for x in ${PATH}; do
> +	[[ ${x} == ${PORTAGE_OVERRIDE_EPREFIX}/usr/lib*/portage/* ]]
> && continue
> +	[[ ${x} == */._portage_reinstall_.* ]] && continue
> +	path+=":${x}"
> +done
> +PATH=${path#:}
> +
>  if [[ "${implementation}" == "c" ]]; then
>  	exec "${INSTALL_XATTR}" "$@"
>  elif [[ "${implementation}" == "python" ]]; then

looks good

-- 
Brian Dolbec <dolsen>