Add --enable-fuzzer-linker and --enable-fuzzer-engine options.

These will allow the fuzzers to be built as part of oss-fuzz.

INSTALL

@@ -181,11 +181,25 @@ Compilation options:
 	https://www.llvm.org/docs/LibFuzzer.html for details.
 	The resulting binaries, beginning with "fuzz_" can be used
 	to test sudo.  This option is generally used in conjunction
-	with --enable-sanitizer.
+	with --enable-sanitizer.  This option requires the clang
+	C compiler--it is not supported by gcc.
 
 	This option should only be used for testing and not in a
 	production environment.
 
+  --enable-fuzzer-engine=library
+        The library to use when linking fuzz targets instead of
+        LLVM's libFuzzer.  It is intended to be set to the path to
+        an alternate fuzzing library, such as AFL++ or Honggfuzz.
+
+  --enable-fuzzer-linker=command
+        An alternate linker command to use when building fuzz
+        targets, instead of clang.  It may be necessary to set this
+        when using the --enable-fuzzer-engine option to link with
+        a fuzzer engine that requires C++ libraries.  For oss-fuzz,
+        this option is used to cause fuzz targets to be linked with
+        clang++.
+
   --disable-hardening
 	Disable the use of compiler/linker exploit mitigation options
 	which are enabled by default.  This includes compiling with

configure

@@ -762,6 +762,8 @@ rundir
 logpath
 log_dir
 iolog_dir
+FUZZ_LD
+FUZZ_ENGINE
 PPFILES
 LIBLOGSRV
 LOGSRVD_CONF
@@ -783,7 +785,6 @@ SSP_CFLAGS
 SSP_LDFLAGS
 PIE_CFLAGS
 PIE_LDFLAGS
-FUZZ_LDFLAGS
 ASAN_CFLAGS
 ASAN_LDFLAGS
 CROSS_COMPILING
@@ -1007,6 +1008,8 @@ enable_hardening
 enable_pie
 enable_sanitizer
 enable_fuzzer
+enable_fuzzer_engine
+enable_fuzzer_linker
 enable_leaks
 enable_poll
 enable_admin_flag
@@ -1709,6 +1712,10 @@ Optional Features:
   --enable-pie            Build sudo as a position independent executable.
   --enable-sanitizer      Build sudo with sanitizer support.
   --enable-fuzzer         Build sudo with LLVM libFuzzer support.
+  --enable-fuzzer-engine  Link fuzz targets with the specified fuzzer engine
+                          instead of the default.
+  --enable-fuzzer-linker  Use the specified linker when building fuzz targets
+                          instead of the default C compiler.
   --disable-leaks         Prevent some harmless memory leaks.
   --disable-poll          Use select() instead of poll().
   --enable-admin-flag     Whether to create a Ubuntu-style admin flag file
@@ -3523,6 +3530,7 @@ printf "%s\n" "$as_me: Configuring Sudo version $PACKAGE_VERSION" >&6;}
 
 
 
+
 
 
 #
@@ -3614,6 +3622,8 @@ INIT_DIR=
 RC_LINK=
 COMPAT_EXP=
 SIGNAME=
+FUZZ_ENGINE=
+FUZZ_LD='$(CC)'
 WEAK_ALIAS=no
 CHECKSHADOW=true
 shadow_funcs=
@@ -6923,6 +6933,34 @@ else $as_nop
 fi
 
 
+# Check whether --enable-fuzzer-engine was given.
+if test ${enable_fuzzer_engine+y}
+then :
+  enableval=$enable_fuzzer_engine;  case "$enableval" in
+    yes)    as_fn_error $? "\"must give --enable-fuzzer-engine an argument.\"" "$LINENO" 5
+	    ;;
+    no)	    ;;
+    *)	    FUZZ_ENGINE="$enableval"
+	    ;;
+  esac
+
+fi
+
+
+# Check whether --enable-fuzzer-linker was given.
+if test ${enable_fuzzer_linker+y}
+then :
+  enableval=$enable_fuzzer_linker;  case "$enableval" in
+    yes)    as_fn_error $? "\"must give --enable-fuzzer-linker an argument.\"" "$LINENO" 5
+	    ;;
+    no)	    ;;
+    *)	    FUZZ_LD="$enableval"
+	    ;;
+  esac
+
+fi
+
+
 # Check whether --enable-leaks was given.
 if test ${enable_leaks+y}
 then :
@@ -28609,39 +28647,9 @@ else $as_nop
 
 fi
 
-
+	if test -z "$FUZZ_ENGINE"; then
-if test ${FUZZ_LDFLAGS+y}
+	    FUZZ_ENGINE="-fsanitize=fuzzer"
-then :
+	fi
-
-  case " $FUZZ_LDFLAGS " in #(
-  *" -fsanitize=fuzzer "*) :
-    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: : FUZZ_LDFLAGS already contains -fsanitize=fuzzer"; } >&5
-  (: FUZZ_LDFLAGS already contains -fsanitize=fuzzer) 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; } ;; #(
-  *) :
-
-     as_fn_append FUZZ_LDFLAGS " -fsanitize=fuzzer"
-     { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: : FUZZ_LDFLAGS=\"\$FUZZ_LDFLAGS\""; } >&5
-  (: FUZZ_LDFLAGS="$FUZZ_LDFLAGS") 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }
-     ;;
-esac
-
-else $as_nop
-
-  FUZZ_LDFLAGS=-fsanitize=fuzzer
-  { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: : FUZZ_LDFLAGS=\"\$FUZZ_LDFLAGS\""; } >&5
-  (: FUZZ_LDFLAGS="$FUZZ_LDFLAGS") 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }
-
-fi
-
 	{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -fno-omit-frame-pointer" >&5
 printf %s "checking whether C compiler accepts -fno-omit-frame-pointer... " >&6; }
 if test ${ax_cv_check_cflags___fno_omit_frame_pointer+y}

configure.ac

@@ -101,7 +101,6 @@ AC_SUBST([SUDOERS_TEST_PROGS])
 AC_SUBST([CROSS_COMPILING])
 AC_SUBST([ASAN_LDFLAGS])
 AC_SUBST([ASAN_CFLAGS])
-AC_SUBST([FUZZ_LDFLAGS])
 AC_SUBST([PIE_LDFLAGS])
 AC_SUBST([PIE_CFLAGS])
 AC_SUBST([SSP_LDFLAGS])
@@ -123,6 +122,8 @@ AC_SUBST([LOGSRVD_SRC])
 AC_SUBST([LOGSRVD_CONF])
 AC_SUBST([LIBLOGSRV])
 AC_SUBST([PPFILES])
+AC_SUBST([FUZZ_ENGINE])
+AC_SUBST([FUZZ_LD])
 
 dnl
 dnl Variables that get substituted in docs (not overridden by environment)
@@ -262,6 +263,8 @@ INIT_DIR=
 RC_LINK=
 COMPAT_EXP=
 SIGNAME=
+FUZZ_ENGINE=
+FUZZ_LD='$(CC)'
 dnl
 dnl Other variables
 dnl
@@ -1534,6 +1537,28 @@ AC_ARG_ENABLE(fuzzer,
 [AS_HELP_STRING([--enable-fuzzer], [Build sudo with LLVM libFuzzer support.])],
 [], [enable_fuzzer=no])
 
+AC_ARG_ENABLE(fuzzer-engine,
+[AS_HELP_STRING([--enable-fuzzer-engine], [Link fuzz targets with the specified fuzzer engine instead of the default.])],
+[ case "$enableval" in
+    yes)    AC_MSG_ERROR(["must give --enable-fuzzer-engine an argument."])
+	    ;;
+    no)	    ;;
+    *)	    FUZZ_ENGINE="$enableval"
+	    ;;
+  esac
+])
+
+AC_ARG_ENABLE(fuzzer-linker,
+[AS_HELP_STRING([--enable-fuzzer-linker], [Use the specified linker when building fuzz targets instead of the default C compiler.])],
+[ case "$enableval" in
+    yes)    AC_MSG_ERROR(["must give --enable-fuzzer-linker an argument."])
+	    ;;
+    no)	    ;;
+    *)	    FUZZ_LD="$enableval"
+	    ;;
+  esac
+])
+
 AC_ARG_ENABLE(leaks,
 [AS_HELP_STRING([--disable-leaks], [Prevent some harmless memory leaks.])],
 [ case "$enableval" in
@@ -4569,7 +4594,9 @@ fi
 if test "$enable_fuzzer" = "yes"; then
     AX_CHECK_COMPILE_FLAG([-fsanitize=fuzzer-no-link], [
 	AX_APPEND_FLAG([-fsanitize=fuzzer-no-link], [ASAN_CFLAGS])
-	AX_APPEND_FLAG([-fsanitize=fuzzer], [FUZZ_LDFLAGS])
+	if test -z "$FUZZ_ENGINE"; then
+	    FUZZ_ENGINE="-fsanitize=fuzzer"
+	fi
 	AX_CHECK_COMPILE_FLAG([-fno-omit-frame-pointer], [
 	    AX_APPEND_FLAG([-fno-omit-frame-pointer], [CFLAGS])
 	])

lib/iolog/Makefile.in

@@ -81,9 +81,10 @@ TEST_LIBS = @LIBS@
 TEST_LDFLAGS = @LDFLAGS@
 
 # Fuzzers
+LIB_FUZZING_ENGINE = @FUZZ_ENGINE@
 FUZZ_PROGS = fuzz_iolog_json fuzz_iolog_legacy fuzz_iolog_timing
-FUZZ_LIBS = @LIBS@
+FUZZ_LIBS = @LIBS@ $(LIB_FUZZING_ENGINE)
-FUZZ_LDFLAGS = @LDFLAGS@ @FUZZ_LDFLAGS@
+FUZZ_LDFLAGS = @LDFLAGS@
 
 # Set to non-empty for development mode
 DEVEL = @DEVEL@
@@ -160,13 +161,13 @@ host_port_test: $(HOST_PORT_TEST_OBJS) libsudo_iolog.la
 	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(HOST_PORT_TEST_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(TEST_LDFLAGS) $(TEST_LIBS)
 
 fuzz_iolog_json: $(FUZZ_IOLOG_JSON_OBJS) libsudo_iolog.la
-	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(FUZZ_IOLOG_JSON_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
+	$(LIBTOOL) $(LTFLAGS) --mode=link @FUZZ_LD@ -o $@ $(FUZZ_IOLOG_JSON_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
 
 fuzz_iolog_legacy: $(FUZZ_IOLOG_LEGACY_OBJS) libsudo_iolog.la
-	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(FUZZ_IOLOG_LEGACY_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
+	$(LIBTOOL) $(LTFLAGS) --mode=link @FUZZ_LD@ -o $@ $(FUZZ_IOLOG_LEGACY_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
 
 fuzz_iolog_timing: $(FUZZ_IOLOG_TIMING_OBJS) libsudo_iolog.la
-	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(FUZZ_IOLOG_TIMING_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
+	$(LIBTOOL) $(LTFLAGS) --mode=link @FUZZ_LD@ -o $@ $(FUZZ_IOLOG_TIMING_OBJS) libsudo_iolog.la $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
 
 pre-install:
 

plugins/sudoers/Makefile.in

@@ -159,9 +159,10 @@ TEST_PROGS = check_addr check_base64 check_digest check_env_pattern \
 	     check_iolog_plugin check_starttime check_unesc @SUDOERS_TEST_PROGS@
 
 # Fuzzers
+LIB_FUZZING_ENGINE = @FUZZ_ENGINE@
 FUZZ_PROGS = fuzz_sudoers fuzz_sudoers_ldif
-FUZZ_LIBS = libparsesudoers.la $(LIBS)
+FUZZ_LIBS = libparsesudoers.la $(LIBS) $(LIB_FUZZING_ENGINE)
-FUZZ_LDFLAGS = @LDFLAGS@ @FUZZ_LDFLAGS@
+FUZZ_LDFLAGS = @LDFLAGS@
 
 AUTH_OBJS = sudo_auth.lo @AUTH_OBJS@
 
@@ -347,10 +348,10 @@ check_symbols: $(CHECK_SYMBOLS_OBJS) $(LIBUTIL)
 	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(CHECK_SYMBOLS_OBJS) $(CHECK_SYMBOLS_LDFLAGS) $(LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(LIBS) @SUDO_LIBS@
 
 fuzz_sudoers: $(FUZZ_SUDOERS_OBJS) libparsesudoers.la $(LIBUTIL)
-	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(FUZZ_SUDOERS_OBJS) $(LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
+	$(LIBTOOL) $(LTFLAGS) --mode=link @FUZZ_LD@ -o $@ $(FUZZ_SUDOERS_OBJS) $(LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
 
 fuzz_sudoers_ldif: $(FUZZ_SUDOERS_LDIF_OBJS) libparsesudoers.la $(LIBUTIL)
-	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(FUZZ_SUDOERS_LDIF_OBJS) $(LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
+	$(LIBTOOL) $(LTFLAGS) --mode=link @FUZZ_LD@ -o $@ $(FUZZ_SUDOERS_LDIF_OBJS) $(LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(FUZZ_LDFLAGS) $(FUZZ_LIBS)
 
 GENERATED = gram.h gram.c toke.c def_data.c def_data.h getdate.c