Add fuzzing for parseRFC1035CharString

diff --git a/fuzzing/README.md b/fuzzing/README.md
index 055c44883008d0b5e78b7a573a31c4c5417430db..b2ad4437c8926b7d4d877067c49ff4cd41581197 100644 (file)
--- a/fuzzing/README.md
+++ b/fuzzing/README.md
@@ -14,6 +14,8 @@ The current targets cover:
 - MOADNSParser (fuzz_target_moadnsparser) ;
 - the Proxy Protocol parser (fuzz_target_proxyprotocol) ;
 - ZoneParserTNG (fuzz_target_zoneparsertng).
+- Parts of the ragel-generated parser (parseRFC1035CharString in
+  fuzz_target_dnslabeltext)
 
 By default the targets are linked against a standalone target,
 pdns/standalone_fuzz_target_runner.cc, which does no fuzzing but makes it easy
@@ -51,3 +53,38 @@ The 'corpus' directory contains three sub-directories:
 When run in the OSS-Fuzz environment, the zone files from the
 regression-tests/zones/ directory are added to the ones present
 in the fuzzing/corpus/zones/ directory.
+
+Quickly getting started (using clang 11)
+----------------------------------------
+First, confgure:
+
+```
+LIB_FUZZING_ENGINE="/usr/lib/clang/11.0.1/lib/linux/libclang_rt.fuzzer-x86_64.a" \
+  CC=clang \
+  CXX=clang++ \
+  CFLAGS='-fsanitize=fuzzer-no-link' \
+  CXXFLAGS='-fsanitize=fuzzer-no-link' \
+  ./configure --without-dynmodules --with-modules= --disable-lua-records --disable-ixfrdist --enable-fuzz-targets --disable-dependency-tracking --disable-silent-rules --enable-asan --enable-ubsan
+```
+
+Then build:
+
+```
+LIB_FUZZING_ENGINE="/usr/lib/clang/11.0.1/lib/linux/libclang_rt.fuzzer-x86_64.a" \
+  make -C pdns -j2 fuzz_targets
+```
+
+Now you're ready to run one of the fuzzing targets.
+First, copy the starting corpus:
+
+```
+mkdir new-corpus
+./pdns/fuzz_target_XXXXXXX -merge=1 new-corpus fuzzing/corpus/YYYYY
+```
+
+Then run the thing:
+```
+./pdns_fuzz_target_XXXXXXX new-corpus
+```
+
+The [LLVM docs](https://llvm.org/docs/LibFuzzer.html) have more info.

diff --git a/fuzzing/corpus/txt-records/escaped b/fuzzing/corpus/txt-records/escaped
new file mode 100644 (file)
index 0000000..0e5ed5e
--- /dev/null
+++ b/fuzzing/corpus/txt-records/escaped
@@ -0,0 +1 @@
+esc\033aped\!

diff --git a/fuzzing/corpus/txt-records/escaped_quoted b/fuzzing/corpus/txt-records/escaped_quoted
new file mode 100644 (file)
index 0000000..881c4da
--- /dev/null
+++ b/fuzzing/corpus/txt-records/escaped_quoted
@@ -0,0 +1 @@
+"esc\033ped!"

diff --git a/fuzzing/corpus/txt-records/quoted_simple b/fuzzing/corpus/txt-records/quoted_simple
new file mode 100644 (file)
index 0000000..3580093
--- /dev/null
+++ b/fuzzing/corpus/txt-records/quoted_simple
@@ -0,0 +1 @@
+"hello"

diff --git a/fuzzing/corpus/txt-records/simple b/fuzzing/corpus/txt-records/simple
new file mode 100644 (file)
index 0000000..ce01362
--- /dev/null
+++ b/fuzzing/corpus/txt-records/simple
@@ -0,0 +1 @@
+hello

diff --git a/pdns/.gitignore b/pdns/.gitignore
index 7b6406ec349b6482b6a1deb230d670d80415f40b..4d24f952bf23ea28343ece94c7a715d713466459 100644 (file)
--- a/pdns/.gitignore
+++ b/pdns/.gitignore
@@ -70,3 +70,4 @@ effective_tld_names.dat
 /fuzz_target_packetcache
 /fuzz_target_proxyprotocol
 /fuzz_target_zoneparsertng
+/fuzz_target_dnslabeltext_parseRFC1035CharString

diff --git a/pdns/Makefile.am b/pdns/Makefile.am
index 975a12972217450bc74b31914151d95e29179cb3..ab0676459498b5995952578a5086ecea37bfa198 100644 (file)
--- a/pdns/Makefile.am
+++ b/pdns/Makefile.am
@@ -1478,7 +1478,8 @@ fuzz_targets_programs =  \
        fuzz_target_moadnsparser \
        fuzz_target_packetcache \
        fuzz_target_proxyprotocol \
-       fuzz_target_zoneparsertng
+       fuzz_target_zoneparsertng \
+       fuzz_target_dnslabeltext_parseRFC1035CharString
 
 fuzz_targets: $(fuzz_targets_programs)
 
@@ -1593,6 +1594,14 @@ fuzz_target_zoneparsertng_DEPENDENCIES = $(fuzz_targets_deps)
 fuzz_target_zoneparsertng_LDFLAGS = $(fuzz_targets_ldflags)
 fuzz_target_zoneparsertng_LDADD = $(fuzz_targets_libs)
 
+fuzz_target_dnslabeltext_parseRFC1035CharString_SOURCES = \
+       dnslabeltext.cc \
+       fuzz_dnslabeltext_parseRFC1035CharString.cc
+
+fuzz_target_dnslabeltext_parseRFC1035CharString_DEPENDENCIES = $(fuzz_targets_deps)
+fuzz_target_dnslabeltext_parseRFC1035CharString_LDFLAGS = $(fuzz_targets_ldflags)
+fuzz_target_dnslabeltext_parseRFC1035CharString_LDADD = $(fuzz_targets_libs)
+
 endif
 
 dnslabeltext.cc: dnslabeltext.rl

diff --git a/pdns/fuzz_dnslabeltext_parseRFC1035CharString.cc b/pdns/fuzz_dnslabeltext_parseRFC1035CharString.cc
new file mode 100644 (file)
index 0000000..4f13a0b
--- /dev/null
+++ b/pdns/fuzz_dnslabeltext_parseRFC1035CharString.cc
@@ -0,0 +1,35 @@
+/*
+ * This file is part of PowerDNS or dnsdist.
+ * Copyright -- PowerDNS.COM B.V. and its contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * In addition, for the avoidance of any doubt, permission is granted to
+ * link this program with OpenSSL and to (re)distribute the binaries
+ * produced as the result of such linking.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "misc.hh"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size);
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+
+  std::string val;
+
+  std::string input((char*)data, size);
+  parseRFC1035CharString(input, val);
+
+  return 0;
+}