git/oss-fuzz/fuzz-config.c
Brian C Tracy fe2033b84f fuzz: add fuzzer for config parsing
Add a new fuzz target that exercises the parsing of git configs.
The existing git_config_from_mem function is a perfect entry point
for fuzzing as it exercises the same code paths as the rest of the
config parsing functions and offers an easily fuzzable interface.

Config parsing is a useful thing to fuzz because it operates on user
controlled data and is a central component of many git operations.

Signed-off-by: Brian C Tracy <brian.tracy33@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-03-15 10:47:05 -07:00

34 lines
993 B
C

#include "git-compat-util.h"
#include "config.h"
int LLVMFuzzerTestOneInput(const uint8_t *, size_t);
static int config_parser_callback(const char *, const char *,
const struct config_context *, void *);
static int config_parser_callback(const char *key, const char *value,
const struct config_context *ctx UNUSED,
void *data UNUSED)
{
/*
* Visit every byte of memory we are given to make sure the parser
* gave it to us appropriately. We need to unconditionally return 0,
* but we also want to prevent the strlen from being optimized away.
*/
size_t c = strlen(key);
if (value)
c += strlen(value);
return c == SIZE_MAX;
}
int LLVMFuzzerTestOneInput(const uint8_t *data, const size_t size)
{
struct config_options config_opts = { 0 };
config_opts.error_action = CONFIG_ERROR_SILENT;
git_config_from_mem(config_parser_callback, CONFIG_ORIGIN_BLOB,
"fuzztest-config", (const char *)data, size, NULL,
CONFIG_SCOPE_UNKNOWN, &config_opts);
return 0;
}