diff options
Diffstat (limited to 'custom_mutators/symcc/symcc.c')
-rw-r--r-- | custom_mutators/symcc/symcc.c | 123 |
1 files changed, 110 insertions, 13 deletions
diff --git a/custom_mutators/symcc/symcc.c b/custom_mutators/symcc/symcc.c index f32f98f8..9c6c0cb8 100644 --- a/custom_mutators/symcc/symcc.c +++ b/custom_mutators/symcc/symcc.c @@ -1,7 +1,10 @@ +#define _GNU_SOURCE #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> +#include <unistd.h> +#include <fcntl.h> #include "config.h" #include "debug.h" #include "afl-fuzz.h" @@ -21,6 +24,7 @@ typedef struct my_mutator { afl_state_t *afl; u8 * mutator_buf; u8 * out_dir; + u8 * tmp_dir; u8 * target; uint32_t seed; @@ -55,10 +59,11 @@ my_mutator_t *afl_custom_init(afl_state_t *afl, unsigned int seed) { 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); } + data->tmp_dir = alloc_printf("%s/tmp", data->out_dir); + setenv("SYMCC_OUTPUT_DIR", data->tmp_dir, 1); int pid = fork(); if (pid == -1) return NULL; @@ -84,6 +89,10 @@ my_mutator_t *afl_custom_init(afl_state_t *afl, unsigned int seed) { if (mkdir(data->out_dir, 0755)) PFATAL("Could not create directory %s", data->out_dir); + + if (mkdir(data->tmp_dir, 0755)) + PFATAL("Could not create directory %s", data->tmp_dir); + DBG("out_dir=%s, target=%s\n", data->out_dir, data->target); return data; @@ -96,33 +105,119 @@ 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(); + int pipefd[2]; + struct stat st; + ACTF("Queueing to symcc: %s", filename_new_queue); + u8 *fn = alloc_printf("%s", filename_new_queue); + if (!(stat(fn, &st) == 0 && S_ISREG(st.st_mode) && st.st_size)) { - if (pid == -1) return; + ck_free(fn); + PFATAL("Couldn't find enqueued file: %s", fn); - if (pid) pid = waitpid(pid, NULL, 0); + } - if (pid == 0) { + if (afl_struct->fsrv.use_stdin) { + + if (pipe(pipefd) == -1) { + + ck_free(fn); + PFATAL("Couldn't create a pipe for interacting with symcc child process"); + + } + + } + + int pid = fork(); - setenv("SYMCC_INPUT_FILE", afl_struct->fsrv.out_file, 1); + if (pid == -1) return; + + if (pid) { if (afl_struct->fsrv.use_stdin) { - u8 *fn = alloc_printf("%s/%s", afl_struct->out_dir, filename_new_queue); + close(pipefd[0]); 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); + close(fd); + if (r <= 0) { + + close(pipefd[1]); + return; + + } + + if (r > fcntl(pipefd[1], F_GETPIPE_SZ)) + fcntl(pipefd[1], F_SETPIPE_SZ, MAX_FILE); + ck_write(pipefd[1], data->mutator_buf, r, filename_new_queue); + + } else { + + ck_free(fn); + close(pipefd[1]); + PFATAL( + "Something happened to the enqueued file before sending its " + "contents to symcc binary"); } + close(pipefd[1]); + + } + + pid = waitpid(pid, NULL, 0); + + // At this point we need to transfer files to output dir, since their names + // collide and symcc will just overwrite them + + struct dirent **nl; + int32_t items = scandir(data->tmp_dir, &nl, NULL, NULL); + u8 * origin_name = basename(filename_new_queue); + int32_t i; + if (items > 0) { + + for (i = 0; i < (u32)items; ++i) { + + struct stat st; + u8 *source_name = alloc_printf("%s/%s", data->tmp_dir, nl[i]->d_name); + u8 *destination_name = + alloc_printf("%s/%s.%s", data->out_dir, origin_name, nl[i]->d_name); + DBG("test=%s\n", fn); + if (stat(source_name, &st) == 0 && S_ISREG(st.st_mode) && st.st_size) { + + rename(source_name, destination_name); + DBG("found=%s\n", source_name); + + } + + ck_free(source_name); + ck_free(destination_name); + free(nl[i]); + + } + + free(nl); + + } + + } + + if (pid == 0) { + + if (afl_struct->fsrv.use_stdin) { + + unsetenv("SYMCC_INPUT_FILE"); + close(pipefd[1]); + dup2(pipefd[0], 0); + + } else { + + setenv("SYMCC_INPUT_FILE", afl_struct->fsrv.out_file, 1); + } DBG("exec=%s\n", data->target); @@ -130,6 +225,7 @@ void afl_custom_queue_new_entry(my_mutator_t * data, 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); @@ -180,7 +276,7 @@ size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf, size_t buf_size, struct dirent **nl; int32_t i, done = 0, items = scandir(data->out_dir, &nl, NULL, NULL); - size_t size = 0; + ssize_t size = 0; if (items <= 0) return 0; @@ -199,6 +295,7 @@ size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf, size_t buf_size, size = read(fd, data->mutator_buf, max_size); *out_buf = data->mutator_buf; + close(fd); done = 1; @@ -217,7 +314,7 @@ size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf, size_t buf_size, free(nl); DBG("FUZZ size=%lu\n", size); - return size; + return (uint32_t)size; } |