optimizations options (e.g. -O0, -O1, -O2) to diversify testing.
* Build a test driver using the same options as the library.
The test driver is a C/C++ file containing interesting calls to the library
- inside a single function ``extern "C" void LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);``
+ inside a single function ``extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);``.
+ Currently, the only expected return value is 0, others are reserved for future.
* Link the Fuzzer, the library and the driver together into an executable
using the same sanitizer options as for the library.
* Collect the initial corpus of inputs for the
max_total_time 0 If positive, indicates the maximal total time in seconds to run the fuzzer.
help 0 Print help.
save_minimized_corpus 0 If 1, the minimized corpus is saved into the first input directory. Example: ./fuzzer -save_minimized_corpus=1 NEW_EMPTY_DIR OLD_CORPUS
+ merge 0 If 1, the 2-nd, 3-rd, etc corpora will be merged into the 1-st corpus. Only interesting units will be taken.
jobs 0 Number of jobs to run. If jobs >= 1 we spawn this number of jobs in separate worker processes with stdout/stderr redirected to fuzz-JOB.log.
workers 0 Number of simultaneous worker processes to run the jobs. If zero, "min(jobs,NumberOfCpuCores()/2)" is used.
sync_command 0 Execute an external command "<sync_command> <test_corpus>" to synchronize the test corpus.
use_traces 0 Experimental: use instruction traces
only_ascii 0 If 1, generate only ASCII (isprint+isspace) inputs.
test_single_input "" Use specified file content as test input. Test will be run only once. Useful for debugging a particular case.
-
+ artifact_prefix "" Write fuzzing artifacts (crash, timeout, or slow inputs) as $(artifact_prefix)file
For the full list of flags run the fuzzer binary with ``-help=1``.
A simple function that does something interesting if it receives the input "HI!"::
cat << EOF >> test_fuzzer.cc
- extern "C" void LLVMFuzzerTestOneInput(const unsigned char *data, unsigned long size) {
+ extern "C" int LLVMFuzzerTestOneInput(const unsigned char *data, unsigned long size) {
if (size > 0 && data[0] == 'H')
if (size > 1 && data[1] == 'I')
if (size > 2 && data[2] == '!')
__builtin_trap();
+ return 0;
}
EOF
# Get lib/Fuzzer. Assuming that you already have fresh clang in PATH.
cat << EOF > pcre_fuzzer.cc
#include <string.h>
#include "pcre2posix.h"
- extern "C" void LLVMFuzzerTestOneInput(const unsigned char *data, size_t size) {
- if (size < 1) return;
+ extern "C" int LLVMFuzzerTestOneInput(const unsigned char *data, size_t size) {
+ if (size < 1) return 0;
char *str = new char[size+1];
memcpy(str, data, size);
str[size] = 0;
regfree(&preg);
}
delete [] str;
+ return 0;
}
EOF
clang++ -g -fsanitize=address $COV_FLAGS -c -std=c++11 -I inst/include/ pcre_fuzzer.cc
assert (SSL_CTX_use_PrivateKey_file(sctx, "server.key", SSL_FILETYPE_PEM));
return 0;
}
- extern "C" void LLVMFuzzerTestOneInput(unsigned char *Data, size_t Size) {
+ extern "C" int LLVMFuzzerTestOneInput(unsigned char *Data, size_t Size) {
static int unused = Init();
SSL *server = SSL_new(sctx);
BIO *sinbio = BIO_new(BIO_s_mem());
BIO_write(sinbio, Data, Size);
SSL_do_handshake(server);
SSL_free(server);
+ return 0;
}
EOF
# Build the fuzzer.
* http://git.musl-libc.org/cgit/musl/commit/?id=39dfd58417ef642307d90306e1c7e50aaec5a35c
* http://www.openwall.com/lists/oss-security/2015/03/30/3
-* pugixml: https://github.com/zeux/pugixml/issues/39
-
-* PCRE: Search for "LLVM fuzzer" in http://vcs.pcre.org/pcre2/code/trunk/ChangeLog?view=markup
-
-* ICU: http://bugs.icu-project.org/trac/ticket/11838
-
-* Freetype: https://savannah.nongnu.org/search/?words=LibFuzzer&type_of_search=bugs&Search=Search&exact=1#options
+* `pugixml <https://github.com/zeux/pugixml/issues/39>`_
-* Linux Kernel's BPF verifier: https://github.com/iovisor/bpf-fuzzer
+* PCRE: Search for "LLVM fuzzer" in http://vcs.pcre.org/pcre2/code/trunk/ChangeLog?view=markup;
+ also in `bugzilla <https://bugs.exim.org/buglist.cgi?bug_status=__all__&content=libfuzzer&no_redirect=1&order=Importance&product=PCRE&query_format=specific>`_
-* LLVM:
+* `ICU <http://bugs.icu-project.org/trac/ticket/11838>`_
- * Clang: https://llvm.org/bugs/show_bug.cgi?id=23057
+* `Freetype <https://savannah.nongnu.org/search/?words=LibFuzzer&type_of_search=bugs&Search=Search&exact=1#options>`_
- * Clang-format: https://llvm.org/bugs/show_bug.cgi?id=23052
+* `Harfbuzz <https://github.com/behdad/harfbuzz/issues/139>`_
- * libc++: https://llvm.org/bugs/show_bug.cgi?id=24411
+* `SQLite <http://www3.sqlite.org/cgi/src/info/088009efdd56160b>`_
- * llvm-as: https://llvm.org/bugs/show_bug.cgi?id=24639
+* `Libxml2
+ <https://bugzilla.gnome.org/buglist.cgi?bug_status=__all__&content=libFuzzer&list_id=68957&order=Importance&product=libxml2&query_format=specific>`_
- * Disassembler:
+* `Linux Kernel's BPF verifier <https://github.com/iovisor/bpf-fuzzer>`_
- * Mips: Discovered a number of untested instructions for the Mips target
- (see valid-mips*.s in http://reviews.llvm.org/rL247405,
- http://reviews.llvm.org/rL247414, http://reviews.llvm.org/rL247416,
- http://reviews.llvm.org/rL247417, http://reviews.llvm.org/rL247420,
- and http://reviews.llvm.org/rL247422) as well some instructions that
- successfully disassembled on ISA's where they were not valid (see
- invalid-xfail.s files in the same commits).
+* LLVM: `Clang <https://llvm.org/bugs/show_bug.cgi?id=23057>`_, `Clang-format <https://llvm.org/bugs/show_bug.cgi?id=23052>`_, `libc++ <https://llvm.org/bugs/show_bug.cgi?id=24411>`_, `llvm-as <https://llvm.org/bugs/show_bug.cgi?id=24639>`_, Disassembler: http://reviews.llvm.org/rL247405, http://reviews.llvm.org/rL247414, http://reviews.llvm.org/rL247416, http://reviews.llvm.org/rL247417, http://reviews.llvm.org/rL247420, http://reviews.llvm.org/rL247422.
.. _pcre2: http://www.pcre.org/
projects / oota-llvm.git / blobdiff