diff options
author | vanhauser-thc <vh@thc.org> | 2023-05-17 15:25:26 +0200 |
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committer | vanhauser-thc <vh@thc.org> | 2023-05-17 15:25:26 +0200 |
commit | 1d0694df86a3ce70ffac2846f36605eac9300abe (patch) | |
tree | c77f4514b2dd1026a245ccd38f8e2683cad0aa63 | |
parent | dfdc6fd12cdae1fe2dab1183f20d3c312a7f2f6d (diff) | |
download | afl++-1d0694df86a3ce70ffac2846f36605eac9300abe.tar.gz |
add symqemu custom mutator
-rw-r--r-- | custom_mutators/symcc/README.md | 2 | ||||
-rw-r--r-- | custom_mutators/symqemu/Makefile | 14 | ||||
-rw-r--r-- | custom_mutators/symqemu/README.md | 11 | ||||
-rw-r--r-- | custom_mutators/symqemu/symqemu.c | 446 | ||||
-rw-r--r-- | docs/Changelog.md | 3 | ||||
-rw-r--r-- | instrumentation/afl-llvm-common.h | 2 | ||||
-rw-r--r-- | test-instr.c | 9 |
7 files changed, 483 insertions, 4 deletions
diff --git a/custom_mutators/symcc/README.md b/custom_mutators/symcc/README.md index 364a348e..a6839a37 100644 --- a/custom_mutators/symcc/README.md +++ b/custom_mutators/symcc/README.md @@ -5,6 +5,8 @@ This uses the symcc to find new paths into the target. Note that this is a just a proof of concept example! It is better to use the fuzzing helpers of symcc, symqemu, Fuzzolic, etc. rather than this. +Also the symqemu custom mutator is better than this. + To use this custom mutator follow the steps in the symcc repository [https://github.com/eurecom-s3/symcc/](https://github.com/eurecom-s3/symcc/) on how to build symcc and how to instrument a target binary (the same target diff --git a/custom_mutators/symqemu/Makefile b/custom_mutators/symqemu/Makefile new file mode 100644 index 00000000..3361ab0f --- /dev/null +++ b/custom_mutators/symqemu/Makefile @@ -0,0 +1,14 @@ + +ifdef DEBUG + CFLAGS += -DDEBUG +endif + +all: symqemu-mutator.so + +CFLAGS += -O3 -funroll-loops + +symqemu-mutator.so: symqemu.c + $(CC) $(CFLAGS) $(CPPFLAGS) -g -I../../include -shared -fPIC -o symqemu-mutator.so symqemu.c + +clean: + rm -f symqemu-mutator.so *.o *~ core diff --git a/custom_mutators/symqemu/README.md b/custom_mutators/symqemu/README.md new file mode 100644 index 00000000..0d5cd4d7 --- /dev/null +++ b/custom_mutators/symqemu/README.md @@ -0,0 +1,11 @@ +# custum mutator: symqemu + +This uses the symcc to find new paths into the target. + +To use this custom mutator follow the steps in the symqemu repository +[https://github.com/eurecom-s3/symqemu/](https://github.com/eurecom-s3/symqemu/) +on how to build symqemu-x86_x64 and put it in your `PATH`. + +just type `make` to build this custom mutator. + +```AFL_CUSTOM_MUTATOR_LIBRARY=custom_mutators/symqemu/symqemu-mutator.so AFL_SYNC_TIME=1 afl-fuzz ...``` diff --git a/custom_mutators/symqemu/symqemu.c b/custom_mutators/symqemu/symqemu.c new file mode 100644 index 00000000..9030397b --- /dev/null +++ b/custom_mutators/symqemu/symqemu.c @@ -0,0 +1,446 @@ +#define _GNU_SOURCE +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <ctype.h> +#include "config.h" +#include "debug.h" +#include "afl-fuzz.h" +#include "common.h" + +afl_state_t *afl_struct; +static u32 debug = 0; + +#define DBG(x...) \ + if (debug) { fprintf(stderr, x); } + +typedef struct my_mutator { + + afl_state_t *afl; + u8 *mutator_buf; + u8 *out_dir; + u8 *queue_dir; + u8 *target; + u8 *symqemu; + u8 *input_file; + u32 counter; + u32 seed; + u32 argc; + u8 **argv; + +} my_mutator_t; + +my_mutator_t *afl_custom_init(afl_state_t *afl, unsigned int seed) { + + if (getenv("AFL_DEBUG")) debug = 1; + + my_mutator_t *data = calloc(1, sizeof(my_mutator_t)); + if (!data) { + + perror("afl_custom_init alloc"); + return NULL; + + } + + char *path = getenv("PATH"); + char *exec_name = "symqemu-x86_64"; + char *token = strtok(path, ":"); + char exec_path[4096]; + + while (token != NULL && data->symqemu == NULL) { + + snprintf(exec_path, sizeof(exec_path), "%s/%s", token, exec_name); + if (access(exec_path, X_OK) == 0) { + + data->symqemu = (u8 *)strdup(exec_path); + break; + + } + + token = strtok(NULL, ":"); + + } + + if (!data->symqemu) FATAL("symqemu binary %s not found", exec_name); + DBG("Found %s\n", data->symqemu); + + if (getenv("AFL_CUSTOM_MUTATOR_ONLY")) + FATAL("the symqemu module cannot be used with AFL_CUSTOM_MUTATOR_ONLY."); + + if ((data->mutator_buf = malloc(MAX_FILE)) == NULL) { + + free(data); + perror("mutator_buf alloc"); + return NULL; + + } + + data->target = getenv("AFL_CUSTOM_INFO_PROGRAM"); + + u8 *path_tmp = getenv("AFL_CUSTOM_INFO_OUT"); + u32 len = strlen(path_tmp) + 32; + u8 *symqemu_path = malloc(len); + data->out_dir = malloc(len); + data->queue_dir = malloc(len); + snprintf(symqemu_path, len, "%s/../symqemu", path_tmp); + snprintf(data->out_dir, len, "%s/../symqemu/out", path_tmp); + snprintf(data->queue_dir, len, "%s/../symqemu/queue", path_tmp); + + mkdir(symqemu_path, 0755); + mkdir(data->out_dir, 0755); + mkdir(data->queue_dir, 0755); + + setenv("SYMCC_OUTPUT_DIR", data->out_dir, 1); + + data->input_file = getenv("AFL_CUSTOM_INFO_PROGRAM_INPUT"); + + u8 *tmp = NULL; + if ((tmp = getenv("AFL_CUSTOM_INFO_PROGRAM_ARGV")) && *tmp) { + + int argc = 0, index = 2; + for (u32 i = 0; i < strlen(tmp); ++i) + if (isspace(tmp[i])) ++argc; + + data->argv = (u8 **)malloc((argc + 4) * sizeof(u8 **)); + u8 *p = strdup(tmp); + + do { + + data->argv[index] = p; + while (*p && !isspace(*p)) + ++p; + if (*p) { + + *p++ = 0; + while (isspace(*p)) + ++p; + + } + + if (strcmp(data->argv[index], "@@") == 0) { + + if (!data->input_file) { + + u32 ilen = strlen(symqemu_path) + 32; + data->input_file = malloc(ilen); + snprintf(data->input_file, ilen, "%s/.input", symqemu_path); + + } + + data->argv[index] = data->input_file; + + } + + DBG("%d: %s\n", index, data->argv[index]); + index++; + + } while (*p); + + data->argv[index] = NULL; + data->argc = index; + + } else { + + data->argv = (u8 **)malloc(8 * sizeof(u8 **)); + data->argc = 2; + data->argv[2] = NULL; + + } + + data->argv[0] = data->symqemu; + data->argv[1] = data->target; + + DBG("out_dir=%s, queue_dir=%s, target=%s, input_file=%s, argc=%u\n", + data->out_dir, data->queue_dir, data->target, + data->input_file ? (char *)data->input_file : (char *)"<stdin>", + data->argc); + + if (data->input_file) { setenv("SYMCC_INPUT_FILE", data->input_file, 1); } + + data->afl = afl; + data->seed = seed; + afl_struct = afl; + + if (debug) { + + fprintf(stderr, "["); + for (u32 i = 0; i <= data->argc; ++i) + fprintf(stderr, " \"%s\"", + data->argv[i] ? (char *)data->argv[i] : "<NULL>"); + fprintf(stderr, " ]\n"); + + } + + OKF("Custom mutator symqemu loaded - note that the initial startup of " + "afl-fuzz will be delayed the more starting seeds are present. This is " + "fine, do not worry!"); + + return data; + +} + +/* When a new queue entry is added we run this input with the symqemu + instrumented binary */ +uint8_t afl_custom_queue_new_entry(my_mutator_t *data, + const uint8_t *filename_new_queue, + const uint8_t *filename_orig_queue) { + + int pipefd[2]; + struct stat st; + if (data->afl->afl_env.afl_no_ui) + ACTF("Sending to symqemu: %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)) { + + ck_free(fn); + PFATAL("Couldn't find enqueued file: %s", fn); + + } + + if (afl_struct->fsrv.use_stdin) { + + if (pipe(pipefd) == -1) { + + ck_free(fn); + PFATAL( + "Couldn't create a pipe for interacting with symqemu child process"); + + } + + } + + int fd = open(fn, O_RDONLY); + if (fd < 0) return 0; + ssize_t r = read(fd, data->mutator_buf, MAX_FILE); + DBG("fn=%s, fd=%d, size=%ld\n", fn, fd, r); + ck_free(fn); + close(fd); + + if (data->input_file) { + + fd = open(data->input_file, O_WRONLY | O_CREAT | O_TRUNC, 0644); + ssize_t s = write(fd, data->mutator_buf, r); + close(fd); + DBG("wrote %zd/%zd to %s\n", s, r, data->input_file); + + } + + int pid = fork(); + + if (pid == -1) return 0; + + if (pid) { + + if (!data->input_file || afl_struct->fsrv.use_stdin) { + + close(pipefd[0]); + + if (fd >= 0) { + + if (r <= 0) { + + close(pipefd[1]); + return 0; + + } + + 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 symqemu binary"); + + } + + close(pipefd[1]); + + } + + pid = waitpid(pid, NULL, 0); + DBG("symqemu finished executing!\n"); + + // At this point we need to transfer files to output dir, since their names + // collide and symqemu will just overwrite them + + struct dirent **nl; + int32_t items = scandir(data->out_dir, &nl, NULL, NULL); + u8 *origin_name = basename(filename_new_queue); + u8 source_name[4096], destination_name[4096]; + int32_t i; + + if (items > 0) { + + for (i = 0; i < (u32)items; ++i) { + + // symqemu output files start with a digit + if (!isdigit(nl[i]->d_name[0])) continue; + + struct stat st; + snprintf(source_name, sizeof(source_name), "%s/%s", data->out_dir, + nl[i]->d_name); + DBG("file=%s\n", source_name); + + if (stat(source_name, &st) == 0 && S_ISREG(st.st_mode) && st.st_size) { + + snprintf(destination_name, sizeof(destination_name), "%s/id:%06u,%s", + data->queue_dir, data->counter++, nl[i]->d_name); + DBG("src=%s dst=%s\n", source_name, destination_name); + rename(source_name, destination_name); + + } + + free(nl[i]); + + } + + free(nl); + + } + + DBG("Done!\n"); + + } else /* (pid == 0) */ { // child + + if (afl_struct->fsrv.use_stdin) { + + close(pipefd[1]); + dup2(pipefd[0], 0); + + } + + DBG("exec=%s\n", data->target); + if (!debug) { + + close(1); + close(2); + dup2(afl_struct->fsrv.dev_null_fd, 1); + dup2(afl_struct->fsrv.dev_null_fd, 2); + + } + + execvp((char *)data->argv[0], (char **)data->argv); + fprintf(stderr, "Executing: ["); + for (u32 i = 0; i <= data->argc; ++i) + fprintf(stderr, " \"%s\"", + data->argv[i] ? (char *)data->argv[i] : "<NULL>"); + fprintf(stderr, " ]\n"); + FATAL("Failed to execute %s %s\n", data->argv[0], data->argv[1]); + exit(-1); + + } + + return 0; + +} + +/* +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 actually just read the files generated from symqemu +/* +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); + ssize_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 (uint32_t)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); + +} + diff --git a/docs/Changelog.md b/docs/Changelog.md index 3602af50..e99747f6 100644 --- a/docs/Changelog.md +++ b/docs/Changelog.md @@ -23,6 +23,9 @@ - qemu_mode: - Persistent mode +QASAN support for ppc32 tragets by @worksbutnottested - a new grammar custom mutator atnwalk was submitted by @voidptr127 ! + - two new custom mutators are now available: + - TritonDSE in custom_mutators/aflpp_tritondse + - SymQEMU in custom_mutators/symqemu ### Version ++4.06c (release) diff --git a/instrumentation/afl-llvm-common.h b/instrumentation/afl-llvm-common.h index c9324460..23f67179 100644 --- a/instrumentation/afl-llvm-common.h +++ b/instrumentation/afl-llvm-common.h @@ -23,7 +23,7 @@ typedef long double max_align_t; #include "llvm/Support/Debug.h" #include "llvm/Support/MathExtras.h" #if LLVM_VERSION_MAJOR < 17 -#include "llvm/Transforms/IPO/PassManagerBuilder.h" + #include "llvm/Transforms/IPO/PassManagerBuilder.h" #endif #if LLVM_VERSION_MAJOR > 3 || \ diff --git a/test-instr.c b/test-instr.c index 1d9f2e6e..eda5189c 100644 --- a/test-instr.c +++ b/test-instr.c @@ -24,7 +24,7 @@ int main(int argc, char **argv) { - int fd = 0; + int fd = 0, cnt; char buff[8]; char *buf = buff; @@ -32,7 +32,6 @@ int main(int argc, char **argv) { if (argc == 2) { buf = argv[1]; - printf("Input %s - ", buf); } else { @@ -47,15 +46,19 @@ int main(int argc, char **argv) { } - if (read(fd, buf, sizeof(buf)) < 1) { + if ((cnt = read(fd, buf, sizeof(buf) - 1)) < 1) { printf("Hum?\n"); return 1; } + buf[cnt] = 0; + } + if (getenv("AFL_DEBUG")) fprintf(stderr, "test-instr: %s\n", buf); + // we support three input cases (plus a 4th if stdin is used but there is no // input) switch (buf[0]) { |