f050124a96
If this patch is applied, and an environment variable is set, all access_check calls will be recorded as seeds for fuzz_security_token_vs_descriptor. See the patch for details. You probably will never want to apply this patch, but it is here just in case. Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz> Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Fuzzing Samba
See also https://wiki.samba.org/index.php/Fuzzing
Fuzzing supplies valid, invalid, unexpected or random data as input to a piece of code. Instrumentation, usually compiler-implemented, is used to monitor for exceptions such as crashes, assertions or memory corruption.
See Wikipedia article on fuzzing for more information.
Honggfuzz
Configure with fuzzing
Example command line to build binaries for use with honggfuzz:
./configure -C --without-gettext --enable-debug --enable-developer \
--address-sanitizer --enable-libfuzzer --abi-check-disable \
CC=.../honggfuzz/hfuzz_cc/hfuzz-clang \
LINK_CC=.../honggfuzz/hfuzz_cc/hfuzz-clang
Fuzzing tiniparser
Example for fuzzing tiniparser using honggfuzz (see --help for more
options):
make bin/fuzz_tiniparser && \
.../honggfuzz/honggfuzz --sanitizers --timeout 3 --max_file_size 256 \
--rlimit_rss 100 -f .../tiniparser-corpus -- bin/fuzz_tiniparser
AFL (american fuzzy lop)
Configure with fuzzing
Example command line to build binaries for use with afl
./configure -C --without-gettext --enable-debug --enable-developer \
--enable-afl-fuzzer --abi-check-disable \
CC=afl-gcc
Fuzzing tiniparser
Example for fuzzing tiniparser using afl-fuzz (see --help for more
options):
make bin/fuzz_tiniparser build && \
afl-fuzz -m 200 -i inputdir -o outputdir -- bin/fuzz_tiniparser
oss-fuzz
Samba can be fuzzed by Google's oss-fuzz system. Assuming you have an oss-fuzz checkout from https://github.com/google/oss-fuzz with Samba's metadata in projects/samba, the following guides will help:
Testing locally
https://google.github.io/oss-fuzz/getting-started/new-project-guide/#testing-locally
Debugging oss-fuzz
See https://google.github.io/oss-fuzz/advanced-topics/debugging/
Samba-specific hints
A typical debugging workflow is:
oss-fuzz$ python infra/helper.py shell samba git fetch $REMOTE $BRANCH git checkout FETCH_HEAD lib/fuzzing/oss-fuzz/build_image.sh compile
This will pull in any new Samba deps and build Samba's fuzzers.