diff options
Diffstat (limited to 'custom_mutators/symcc/symcc.c')
| -rw-r--r-- | custom_mutators/symcc/symcc.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/custom_mutators/symcc/symcc.c b/custom_mutators/symcc/symcc.c new file mode 100644 index 00000000..6f14052f --- /dev/null +++ b/custom_mutators/symcc/symcc.c @@ -0,0 +1,234 @@ +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include "config.h" +#include "debug.h" +#include "afl-fuzz.h" +#include "common.h" + +afl_state_t *afl_struct; + +#ifdef DEBUG + #define DBG(x...) fprintf(stderr, x) +#else + #define DBG(x...) \ + {} +#endif + +typedef struct my_mutator { + + afl_state_t *afl; + u8 * mutator_buf; + u8 * out_dir; + u8 * target; + uint32_t seed; + +} my_mutator_t; + +my_mutator_t *afl_custom_init(afl_state_t *afl, unsigned int seed) { + + if (getenv("AFL_CUSTOM_MUTATOR_ONLY")) + FATAL("the symcc module cannot be used with AFL_CUSTOM_MUTATOR_ONLY."); + + my_mutator_t *data = calloc(1, sizeof(my_mutator_t)); + if (!data) { + + perror("afl_custom_init alloc"); + return NULL; + + } + + if ((data->mutator_buf = malloc(MAX_FILE)) == NULL) { + + perror("mutator_buf alloc"); + return NULL; + + } + + if (!(data->target = getenv("SYMCC_TARGET"))) + FATAL( + "SYMCC_TARGET not defined, this should point to the full path of the " + "symcc compiled binary."); + + if (!(data->out_dir = getenv("SYMCC_OUTPUT_DIR"))) { + + data->out_dir = alloc_printf("%s/symcc", afl->out_dir); + setenv("SYMCC_OUTPUT_DIR", data->out_dir, 1); + + } + + int pid = fork(); + + if (pid == -1) return NULL; + + if (pid) pid = waitpid(pid, NULL, 0); + + if (pid == 0) { + + char *args[4]; + args[0] = "/bin/rm"; + args[1] = "-rf"; + args[2] = data->out_dir; + args[3] = NULL; + execvp(args[0], args); + DBG("exec:FAIL\n"); + exit(-1); + + } + + data->afl = afl; + data->seed = seed; + afl_struct = afl; + + if (mkdir(data->out_dir, 0755)) + PFATAL("Could not create directory %s", data->out_dir); + DBG("out_dir=%s, target=%s\n", data->out_dir, data->target); + + return data; + +} + +/* When a new queue entry is added we run this input with the symcc + instrumented binary */ +void afl_custom_queue_new_entry(my_mutator_t * data, + const uint8_t *filename_new_queue, + const uint8_t *filename_orig_queue) { + + int pid = fork(); + + if (pid == -1) return; + + if (pid) pid = waitpid(pid, NULL, 0); + + if (pid == 0) { + + setenv("SYMCC_INPUT_FILE", afl_struct->fsrv.out_file, 1); + + if (afl_struct->fsrv.use_stdin) { + + u8 *fn = alloc_printf("%s/%s", afl_struct->out_dir, filename_new_queue); + int fd = open(fn, O_RDONLY); + + if (fd >= 0) { + + ssize_t r = read(fd, data->mutator_buf, MAX_FILE); + close(fd); + DBG("fn=%s, fd=%d, size=%ld\n", fn, fd, r); + if (r <= 0) return; + close(0); + ck_write(0, data->mutator_buf, r, fn); + ck_free(fn); + + } + + } + + DBG("exec=%s\n", data->target); + close(1); + close(2); + dup2(afl_struct->fsrv.dev_null_fd, 1); + dup2(afl_struct->fsrv.dev_null_fd, 2); + execvp(data->target, afl_struct->argv); + DBG("exec=FAIL\n"); + exit(-1); + + } + +} + +uint32_t afl_custom_fuzz_count(my_mutator_t *data, const u8 *buf, + size_t buf_size) { + + uint32_t count = 0, i; + struct dirent **nl; + int32_t items = scandir(data->out_dir, &nl, NULL, NULL); + + if (items > 0) { + + for (i = 0; i < (u32)items; ++i) { + + struct stat st; + u8 * fn = alloc_printf("%s/%s", data->out_dir, nl[i]->d_name); + DBG("test=%s\n", fn); + if (stat(fn, &st) == 0 && S_ISREG(st.st_mode) && st.st_size) { + + DBG("found=%s\n", fn); + count++; + + } + + ck_free(fn); + free(nl[i]); + + } + + free(nl); + + } + + DBG("dir=%s, count=%u\n", data->out_dir, count); + return count; + +} + +/* here we actualy just read the files generated from symcc */ +size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf, size_t buf_size, + u8 **out_buf, uint8_t *add_buf, size_t add_buf_size, + size_t max_size) { + + struct dirent **nl; + int32_t i, done = 0, items = scandir(data->out_dir, &nl, NULL, NULL); + size_t size = 0; + + if (items <= 0) return 0; + + for (i = 0; i < (u32)items; ++i) { + + struct stat st; + u8 * fn = alloc_printf("%s/%s", data->out_dir, nl[i]->d_name); + + if (done == 0) { + + if (stat(fn, &st) == 0 && S_ISREG(st.st_mode) && st.st_size) { + + int fd = open(fn, O_RDONLY); + + if (fd >= 0) { + + size = read(fd, data->mutator_buf, max_size); + *out_buf = data->mutator_buf; + close(fd); + done = 1; + + } + + } + + unlink(fn); + + } + + ck_free(fn); + free(nl[i]); + + } + + free(nl); + DBG("FUZZ size=%lu\n", size); + return size; + +} + +/** + * Deinitialize everything + * + * @param data The data ptr from afl_custom_init + */ +void afl_custom_deinit(my_mutator_t *data) { + + free(data->mutator_buf); + free(data); + +} + |