fuzz: allow building fuzzers outside of oss-fuzz

Add a new -Dllvm-fuzz=true option that can be used to build against
libFuzzer and update the oss-fuzz script to work outside of the
oss-fuzz build environment.

diff --git a/meson.build b/meson.build
index df79a54..2e3898b 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -268,8 +268,16 @@ if get_option('tests') != 'false'
         endif
 endif
 
-ossfuzz = get_option('oss-fuzz')
-if ossfuzz
+want_ossfuzz = get_option('oss-fuzz')
+want_libfuzzer = get_option('llvm-fuzz')
+fuzzer_build = want_ossfuzz or want_libfuzzer
+if want_ossfuzz and want_libfuzzer
+        error('only one of oss-fuzz and llvm-fuzz can be specified')
+endif
+if want_libfuzzer
+        fuzzing_engine = meson.get_compiler('cpp').find_library('Fuzzer')
+endif
+if want_ossfuzz
         fuzzing_engine = meson.get_compiler('cpp').find_library('FuzzingEngine')
 endif
 
@@ -316,7 +324,7 @@ endforeach
 
 # the oss-fuzz fuzzers are not built with -fPIE, so don't
 # enable it when we are linking against them
-if not ossfuzz
+if not fuzzer_build
         if cc.has_argument('-fPIE')
               add_project_arguments('-fPIE', language : 'c')
         endif
@@ -372,7 +380,7 @@ foreach arg : ['-Wl,-z,relro',
                            cc.cmd_array(), '-x', 'c', arg,
                            '-include', link_test_c).returncode() == 0
         message('Linking with @0@ supported: @1@'.format(arg, have ? 'yes' : 'no'))
-        if have and (arg != '-pie' or not ossfuzz)
+        if have and (arg != '-pie' or not fuzzer_build)
                 add_project_link_arguments(arg, language : 'c')
         endif
 endforeach
@@ -780,10 +788,10 @@ endif
 
 libmount = dependency('mount',
                       version : '>= 2.30',
-                      required : not ossfuzz)
+                      required : not fuzzer_build)
 
 want_seccomp = get_option('seccomp')
-if want_seccomp != 'false' and not ossfuzz
+if want_seccomp != 'false' and not fuzzer_build
         libseccomp = dependency('libseccomp',
                                 version : '>= 2.3.1',
                                 required : want_seccomp == 'true')
@@ -796,7 +804,7 @@ conf.set10('HAVE_SECCOMP', have)
 m4_defines += have ? ['-DHAVE_SECCOMP'] : []
 
 want_selinux = get_option('selinux')
-if want_selinux != 'false' and not ossfuzz
+if want_selinux != 'false' and not fuzzer_build
         libselinux = dependency('libselinux',
                                 version : '>= 2.1.9',
                                 required : want_selinux == 'true')
@@ -809,7 +817,7 @@ conf.set10('HAVE_SELINUX', have)
 m4_defines += have ? ['-DHAVE_SELINUX'] : []
 
 want_apparmor = get_option('apparmor')
-if want_apparmor != 'false' and not ossfuzz
+if want_apparmor != 'false' and not fuzzer_build
         libapparmor = dependency('libapparmor',
                                  required : want_apparmor == 'true')
         have = libapparmor.found()
@@ -829,7 +837,7 @@ endif
 want_polkit = get_option('polkit')
 install_polkit = false
 install_polkit_pkla = false
-if want_polkit != 'false' and not ossfuzz
+if want_polkit != 'false' and not fuzzer_build
         install_polkit = true
 
         libpolkit = dependency('polkit-gobject-1',
@@ -842,7 +850,7 @@ endif
 conf.set10('ENABLE_POLKIT', install_polkit)
 
 want_acl = get_option('acl')
-if want_acl != 'false' and not ossfuzz
+if want_acl != 'false' and not fuzzer_build
         libacl = cc.find_library('acl', required : want_acl == 'true')
         have = libacl.found()
 else
@@ -853,7 +861,7 @@ conf.set10('HAVE_ACL', have)
 m4_defines += have ? ['-DHAVE_ACL'] : []
 
 want_audit = get_option('audit')
-if want_audit != 'false' and not ossfuzz
+if want_audit != 'false' and not fuzzer_build
         libaudit = dependency('audit', required : want_audit == 'true')
         have = libaudit.found()
 else
@@ -863,7 +871,7 @@ endif
 conf.set10('HAVE_AUDIT', have)
 
 want_blkid = get_option('blkid')
-if want_blkid != 'false' and not ossfuzz
+if want_blkid != 'false' and not fuzzer_build
         libblkid = dependency('blkid', required : want_blkid == 'true')
         have = libblkid.found()
 else
@@ -873,7 +881,7 @@ endif
 conf.set10('HAVE_BLKID', have)
 
 want_kmod = get_option('kmod')
-if want_kmod != 'false' and not ossfuzz
+if want_kmod != 'false' and not fuzzer_build
         libkmod = dependency('libkmod',
                              version : '>= 15',
                              required : want_kmod == 'true')
@@ -885,7 +893,7 @@ endif
 conf.set10('HAVE_KMOD', have)
 
 want_pam = get_option('pam')
-if want_pam != 'false' and not ossfuzz
+if want_pam != 'false' and not fuzzer_build
         libpam = cc.find_library('pam', required : want_pam == 'true')
         libpam_misc = cc.find_library('pam_misc', required : want_pam == 'true')
         have = libpam.found() and libpam_misc.found()
@@ -898,7 +906,7 @@ conf.set10('HAVE_PAM', have)
 m4_defines += have ? ['-DHAVE_PAM'] : []
 
 want_microhttpd = get_option('microhttpd')
-if want_microhttpd != 'false' and not ossfuzz
+if want_microhttpd != 'false' and not fuzzer_build
         libmicrohttpd = dependency('libmicrohttpd',
                                    version : '>= 0.9.33',
                                    required : want_microhttpd == 'true')
@@ -911,7 +919,7 @@ conf.set10('HAVE_MICROHTTPD', have)
 m4_defines += have ? ['-DHAVE_MICROHTTPD'] : []
 
 want_libcryptsetup = get_option('libcryptsetup')
-if want_libcryptsetup != 'false' and not ossfuzz
+if want_libcryptsetup != 'false' and not fuzzer_build
         libcryptsetup = dependency('libcryptsetup',
                                    version : '>= 1.6.0',
                                    required : want_libcryptsetup == 'true')
@@ -923,7 +931,7 @@ endif
 conf.set10('HAVE_LIBCRYPTSETUP', have)
 
 want_libcurl = get_option('libcurl')
-if want_libcurl != 'false' and not ossfuzz
+if want_libcurl != 'false' and not fuzzer_build
         libcurl = dependency('libcurl',
                              version : '>= 7.32.0',
                              required : want_libcurl == 'true')
@@ -941,7 +949,7 @@ if want_libidn == 'true' and want_libidn2 == 'true'
         error('libidn and libidn2 cannot be requested simultaneously')
 endif
 
-if want_libidn != 'false' and want_libidn2 != 'true' and not ossfuzz
+if want_libidn != 'false' and want_libidn2 != 'true' and not fuzzer_build
         libidn = dependency('libidn',
                             required : want_libidn == 'true')
         have = libidn.found()
@@ -951,7 +959,7 @@ else
 endif
 conf.set10('HAVE_LIBIDN', have)
 m4_defines += have ? ['-DHAVE_LIBIDN'] : []
-if not have and want_libidn2 != 'false' and not ossfuzz
+if not have and want_libidn2 != 'false' and not fuzzer_build
         # libidn is used for both libidn and libidn2 objects
         libidn = dependency('libidn2',
                             required : want_libidn2 == 'true')
@@ -963,7 +971,7 @@ conf.set10('HAVE_LIBIDN2', have)
 m4_defines += have ? ['-DHAVE_LIBIDN2'] : []
 
 want_libiptc = get_option('libiptc')
-if want_libiptc != 'false' and not ossfuzz
+if want_libiptc != 'false' and not fuzzer_build
         libiptc = dependency('libiptc',
                              required : want_libiptc == 'true')
         have = libiptc.found()
@@ -975,7 +983,7 @@ conf.set10('HAVE_LIBIPTC', have)
 m4_defines += have ? ['-DHAVE_LIBIPTC'] : []
 
 want_qrencode = get_option('qrencode')
-if want_qrencode != 'false' and not ossfuzz
+if want_qrencode != 'false' and not fuzzer_build
         libqrencode = dependency('libqrencode',
                                  required : want_qrencode == 'true')
         have = libqrencode.found()
@@ -986,7 +994,7 @@ endif
 conf.set10('HAVE_QRENCODE', have)
 
 want_gcrypt = get_option('gcrypt')
-if want_gcrypt != 'false' and not ossfuzz
+if want_gcrypt != 'false' and not fuzzer_build
         libgcrypt = cc.find_library('gcrypt', required : want_gcrypt == 'true')
         libgpg_error = cc.find_library('gpg-error', required : want_gcrypt == 'true')
         have = libgcrypt.found() and libgpg_error.found()
@@ -1001,7 +1009,7 @@ endif
 conf.set10('HAVE_GCRYPT', have)
 
 want_gnutls = get_option('gnutls')
-if want_gnutls != 'false' and not ossfuzz
+if want_gnutls != 'false' and not fuzzer_build
         libgnutls = dependency('gnutls',
                                version : '>= 3.1.4',
                                required : want_gnutls == 'true')
@@ -1013,7 +1021,7 @@ endif
 conf.set10('HAVE_GNUTLS', have)
 
 want_elfutils = get_option('elfutils')
-if want_elfutils != 'false' and not ossfuzz
+if want_elfutils != 'false' and not fuzzer_build
         libdw = dependency('libdw',
                            required : want_elfutils == 'true')
         have = libdw.found()
@@ -1024,7 +1032,7 @@ endif
 conf.set10('HAVE_ELFUTILS', have)
 
 want_zlib = get_option('zlib')
-if want_zlib != 'false' and not ossfuzz
+if want_zlib != 'false' and not fuzzer_build
         libz = dependency('zlib',
                           required : want_zlib == 'true')
         have = libz.found()
@@ -1035,7 +1043,7 @@ endif
 conf.set10('HAVE_ZLIB', have)
 
 want_bzip2 = get_option('bzip2')
-if want_bzip2 != 'false' and not ossfuzz
+if want_bzip2 != 'false' and not fuzzer_build
         libbzip2 = cc.find_library('bz2',
                                    required : want_bzip2 == 'true')
         have = libbzip2.found()
@@ -1046,7 +1054,7 @@ endif
 conf.set10('HAVE_BZIP2', have)
 
 want_xz = get_option('xz')
-if want_xz != 'false' and not ossfuzz
+if want_xz != 'false' and not fuzzer_build
         libxz = dependency('liblzma',
                            required : want_xz == 'true')
         have = libxz.found()
@@ -1057,7 +1065,7 @@ endif
 conf.set10('HAVE_XZ', have)
 
 want_lz4 = get_option('lz4')
-if want_lz4 != 'false' and not ossfuzz
+if want_lz4 != 'false' and not fuzzer_build
         liblz4 = dependency('liblz4',
                             required : want_lz4 == 'true')
         have = liblz4.found()
@@ -1068,7 +1076,7 @@ endif
 conf.set10('HAVE_LZ4', have)
 
 want_xkbcommon = get_option('xkbcommon')
-if want_xkbcommon != 'false' and not ossfuzz
+if want_xkbcommon != 'false' and not fuzzer_build
         libxkbcommon = dependency('xkbcommon',
                                   version : '>= 0.3.0',
                                   required : want_xkbcommon == 'true')
@@ -1080,7 +1088,7 @@ endif
 conf.set10('HAVE_XKBCOMMON', have)
 
 want_glib = get_option('glib')
-if want_glib != 'false' and not ossfuzz
+if want_glib != 'false' and not fuzzer_build
         libglib =    dependency('glib-2.0',
                                 version : '>= 2.22.0',
                                 required : want_glib == 'true')
@@ -1099,7 +1107,7 @@ endif
 conf.set10('HAVE_GLIB', have)
 
 want_dbus = get_option('dbus')
-if want_dbus != 'false' and not ossfuzz
+if want_dbus != 'false' and not fuzzer_build
         libdbus = dependency('dbus-1',
                              version : '>= 1.3.2',
                              required : want_dbus == 'true')
@@ -1111,7 +1119,7 @@ endif
 conf.set10('HAVE_DBUS', have)
 
 default_dnssec = get_option('default-dnssec')
-if ossfuzz
+if fuzzer_build
         default_dnssec = 'no'
 endif
 if default_dnssec != 'no' and conf.get('HAVE_GCRYPT') == 0
@@ -2484,7 +2492,7 @@ foreach tuple : fuzzers
         defs = tuple.length() >= 4 ? tuple[3] : []
         incs = tuple.length() >= 5 ? tuple[4] : includes
 
-        if ossfuzz
+        if fuzzer_build
                 dependencies += fuzzing_engine
         else
                 sources += 'src/fuzz/fuzz-main.c'

diff --git a/meson_options.txt b/meson_options.txt
index 9e7cad7..eda5a57 100644 (file)
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -294,3 +294,5 @@ option('install-tests', type : 'boolean', value : 'false',
 
 option('oss-fuzz', type : 'boolean', value : 'false',
        description : 'build against oss-fuzz')
+option('llvm-fuzz', type : 'boolean', value : 'false',
+       description : 'build against LLVM libFuzzer')

diff --git a/scripts/oss-fuzz.sh b/scripts/oss-fuzz.sh
index beb9d05..8ae7625 100755 (executable)
--- a/scripts/oss-fuzz.sh
+++ b/scripts/oss-fuzz.sh
@@ -20,15 +20,27 @@ set -ex
 
 export LC_CTYPE=C.UTF-8
 
-if [ -z "$WORK" ]; then
-         echo '$WORK must be set'
-         exit 1
-fi
+SANITIZER=${SANITIZER:-address -fsanitize-address-use-after-scope}
+flags="-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=$SANITIZER -fsanitize-coverage=trace-pc-guard,trace-cmp"
+
+export CFLAGS=${CFLAGS:-$flags}
+export CXXFLAGS=${CXXFLAGS:-$flags}
+export CC=${CC:-clang}
+export CXX=${CXX:-clang++}
+export WORK=${WORK:-$(pwd)}
+export OUT=${OUT:-$(pwd)/out}
+mkdir -p $OUT
+
 build=$WORK/build
 rm -rf $build
 mkdir -p $build
 
-meson $build -Doss-fuzz=true -Db_lundef=false
+fuzzflag="oss-fuzz=true"
+if [ -z "$FUZZING_ENGINE" ]; then
+        fuzzflag="llvm-fuzz=true"
+fi
+
+meson $build -D$fuzzflag -Db_lundef=false
 ninja -C $build fuzzers
 
 # get DNS packet corpus
@@ -40,4 +52,4 @@ mkdir -p $OUT/src/shared
 mv $build/src/shared/libsystemd-shared-*.so $OUT/src/shared
 
 find $build -maxdepth 1 -type f -executable -name "fuzz-*" -exec mv {} $OUT \;
-mv $build/*.so src/fuzz/*.options $OUT
+cp src/fuzz/*.options $OUT