Bug 521038 – app-forensics/foremost fails to compile with format-security

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Agostino Sarubbo 2014-08-26 10:57:32 UTC]

This is an auto-filled bug because this package fails to compile with format-security. To reproduce use CFLAGS -Werror=format-security.

Portage 2.2.8-r1 (default/linux/amd64/13.0, gcc-4.7.3, glibc-2.19-r1, 3.2.61-hardened-r2-xxxx-std-ipv6-64 x86_64)
=================================================================
System uname: Linux-3.2.61-hardened-r2-xxxx-std-ipv6-64-x86_64-Intel-R-_Xeon-R-_CPU_E3-1245_V2_@_3.40GHz-with-gentoo-2.2
KiB Mem:    32857344 total,  21548488 free
KiB Swap:          0 total,         0 free
ld ld di GNU (Gentoo 2.23.2 p1.0) 2.23.2
app-shells/bash:          4.2_p45
dev-java/java-config:     2.2.0
dev-lang/python:          2.7.7, 3.2.5-r6, 3.3.5-r1
dev-util/cmake:           2.8.12.2-r1
dev-util/pkgconfig:       0.28-r1
sys-apps/baselayout:      2.2
sys-apps/openrc:          0.12.4
sys-apps/sandbox:         2.6-r1
sys-devel/autoconf:       2.13, 2.69
sys-devel/automake:       1.13.4
sys-devel/binutils:       2.23.2
sys-devel/gcc:            4.7.3-r1
sys-devel/gcc-config:     1.7.3
sys-devel/libtool:        2.4.2-r1
sys-devel/make:           3.82-r4
sys-kernel/linux-headers: 3.13 (virtual/os-headers)
sys-libs/glibc:           2.19-r1
Repositories: gentoo x-portage
ACCEPT_KEYWORDS="amd64"
ACCEPT_LICENSE="*"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=native -Wformat -Werror=format-security -g0 -O2"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/share/config /usr/share/gnupg/qualified.txt"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.3/ext-active/ /etc/php/apache2-php5.4/ext-active/ 
/etc/php/apache2-php5.5/ext-active/ /etc/php/cgi-php5.3/ext-active/ /etc/php/cgi-php5.4/ext-active/ /etc/php/cgi-php5.5/ext-active/ /etc/php/cli-php5.3/ext-active/ 
/etc/php/cli-php5.4/ext-active/ /etc/php/cli-php5.5/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d 
/etc/texmf/updmap.d /etc/texmf/web2c"
CXXFLAGS="-march=native -Wformat -Werror=format-security -g0 -O2"
DISTDIR="/usr/portage/distfiles"
EMERGE_DEFAULT_OPTS="--with-bdeps y --keep-going y -1"
FCFLAGS="-O2 -pipe"
FEATURES="assume-digests binpkg-logs collision-protect config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync multilib-strict news parallel-fetch preserve-libs 
protect-owned sandbox sfperms sign split-log strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync"
FFLAGS="-O2 -pipe"
GENTOO_MIRRORS="http://distfiles.gentoo.org"
LANG="it_IT.UTF-8"
LDFLAGS="-Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu"
MAKEOPTS="-j8"
PKGDIR="/root/.pkg"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 
--exclude=/distfiles --exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/local/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="X acl amd64 berkdb bzip2 cairo cli consolekit cracklib crypt cxx dbus dri fortran gdbm gudev hwdb iconv icu ipv6 jpeg minizip mmx modules multilib ncurses nls nptl ogg openmp pam 
pax_kernel pcre png policykit python qt3support qt4 readline session sse sse2 ssl tcpd unicode vorbis zlib" ABI_X86="64" ELIBC="glibc" KERNEL="linux" 
LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="am fil zh af ca cs da de el es et gl hu nb nl pl pt ro ru sk sl sv uk bg cy en eo fo ga he id ku lt lv mk ms nn 
sw tn zu ja zh_TW en_GB pt_BR ko zh_CN ar en_CA fi kk oc sr tr fa wa nds as be bn bn_BD bn_IN en_US es_AR es_CL es_ES es_MX eu fy fy_NL ga_IE gu gu_IN hi hi_IN is ka kn ml mr nn_NO or 
pa pa_IN pt_PT rm si sq sv_SE ta ta_LK te th vi ast dz km my om sh ug uz ca@valencia sr@ijekavian sr@ijekavianlatin sr@latin csb hne mai se es_LA fr_CA zh_HK br la no es_CR et_EE 
sr_CS bo hsb hy mn sr@Latn lb ne bs tg uz@cyrillic xh be_BY brx ca_XV dgo en_ZA gd kok ks ky lo mni nr ns pap ps rw sa_IN sat sd ss st sw_TZ ti ts ve mt ia az me tl ak hy_AM lg nso 
son ur_PK it fr nb nb_NO hr nan ur tk cs_CZ da_DK de_1901 de_CH en_AU lt_LT pl_PL sa sk_SK th_TH ta_IN tt sco ha mi ven ar_SY el_GR ro_RO ru_RU sl_SI uk_UA vi_VN ar_SY te_IN de_DE 
es_VE fa_IR fr_FR hu_HU id_ID it_IT ja_JP ka_GE nl_NL sr_BA sr_RS ca_ES fi_FI he_IL jv ru_gold yi eu_ES" NGINX_MODULES_HTTP="access auth_basic autoindex browser charset empty_gif 
fastcgi geo gzip limit_conn limit_req map memcached proxy referer rewrite scgi split_clients ssi upstream_ip_hash userid uwsgi addition auth_pam cache_purge dav dav_ext degradation 
echo fancyindex flv geoip gunzip gzip_static headers_more image_filter lua metrics mp4 naxsi perl push push_stream random_index realip secure_link security slowfs_cache spdy 
stub_status sub upload_progress upstream_check xslt ajp auth_request mogilefs sticky" NGINX_MODULES_MAIL="imap pop3 smtp" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-4 
php5-5" PYTHON_SINGLE_TARGET="python2_7 python3_3" PYTHON_TARGETS="python2_7 python3_3" RUBY_TARGETS="ruby19 ruby20" USERLAND="GNU"
USE_PYTHON="2.7 3.3"

[Comment 1 Agostino Sarubbo 2014-08-26 10:57:33 UTC]

Created attachment 383676 [details]
foremost-1.5.7-r1:20140825-233636.log

build log

[Comment 2 Mike Auty (RETIRED) 2014-08-31 00:38:56 UTC]

Firstly, both

CFLAGS="-Werror=format-security" emerge -1av foremost
CFLAGS="-D_FORTIFY_SOURCE=2" emerge -1av foremost

compiled without issue.  To force the error, I had to use:

CFLAGS="-Wformat -Werror=format-security" emerge -1av foremost

so it might be worth updating the automated text and/or the blocked bug.

Investigating the code, it really doesn't look like there's any problem (the user input is converted to numbers earlier, stored in a format string that is based off a constant) however at the same time, there's little point in what they were doing either (using sprintf to copy from one string to another only to use the new string once and then neither of the strings ever again).

I've put a patch into the tree which we can lug around if this is considered a big enough issue, but I'm not a professional C programmer, and I couldn't say what impact the patch will have on the security or normal operation of the program, only that it eliminates this warning.