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fuzz: fix cl_load fuzz target

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I found two issues with the cl_load fuzz targets, one of which impacts
the scanfile and scanmap fuzz targets:

1. We were defining the preprocessor definitions incorrectly using
  "SCAN_TARGETS" instead of "TARGET" in unit_tests/CMakeLists.txt.
  For the scan fuzz targets this meant it wasn't properly defining
  unique settings for each compiled target.
  For the cl_load fuzz target it's worse, it wasn't setting the
  database file name correctly which means it rejected the filenames
  entirely for not having a legitimate suffix.

2. We were pre-compiling the engine before loading signatures.
  You can't load sigs for an engine that's already compiled, so this
  would also fail right away without trying to load any sigs.
This commit is contained in:
micasnyd 2021-12-15 19:22:14 -08:00 • committed by Micah Snyder
parent 4691b78000
commit 0037f5825b
2 changed files with 32 additions and 15 deletions
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41
fuzz/clamav_dbload_fuzzer.cpp
View file

@ -51,8 +51,6 @@ class ClamAVState
cl_set_clcb_msg(clamav_message_callback);
cl_init(CL_INIT_DEFAULT);
engine = cl_engine_new();
cl_engine_compile(engine);
dboptions =
CL_DB_PHISHING | CL_DB_PHISHING_URLS |
@ -99,14 +97,11 @@ class ClamAVState
~ClamAVState()
{
cl_engine_free(engine);
if (NULL != tmp_db_name) {
unlink(tmp_db_name);
}
}
struct cl_engine* engine;
const char* tmp_db_name;
unsigned int dboptions;
};
@ -117,18 +112,40 @@ ClamAVState kClamAVState;
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
{
unsigned int sigs = 0;
FILE* fuzzdb = NULL;
cl_error_t ret;
unsigned int sigs = 0;
FILE* fuzzdb = NULL;
struct cl_engine* engine = NULL;
fuzzdb = fopen(kClamAVState.tmp_db_name, "w");
fwrite(data, size, 1, fuzzdb);
fclose(fuzzdb);
cl_load(
kClamAVState.tmp_db_name,
kClamAVState.engine,
&sigs,
kClamAVState.dboptions);
/* need new engine each time. can't add sigs to compiled engine */
engine = cl_engine_new();
/* load the fuzzer-generated sig db */
if (CL_SUCCESS != (ret = cl_load(
kClamAVState.tmp_db_name,
engine,
&sigs,
kClamAVState.dboptions))) {
printf("cl_load: %s\n", cl_strerror(ret));
goto done;
}
/* build engine */
if (CL_SUCCESS != (ret = cl_engine_compile(engine))) {
printf("cl_engine_compile: %s\n", cl_strerror(ret));
goto done;
}
done:
/* Clean up for the next round */
if (NULL != engine) {
cl_engine_free(engine);
}
return 0;
}