diff options
29 files changed, 2208 insertions, 67 deletions
diff --git a/GNUmakefile b/GNUmakefile index 8ea64109..98092f11 100644 --- a/GNUmakefile +++ b/GNUmakefile @@ -445,6 +445,7 @@ clean: -$(MAKE) -C gcc_plugin clean $(MAKE) -C libdislocator clean $(MAKE) -C libtokencap clean + $(MAKE) -C examples/afl_network_proxy clean $(MAKE) -C examples/socket_fuzzing clean $(MAKE) -C examples/argv_fuzzing clean $(MAKE) -C qemu_mode/unsigaction clean @@ -468,6 +469,7 @@ distrib: all radamsa -$(MAKE) -C gcc_plugin $(MAKE) -C libdislocator $(MAKE) -C libtokencap + $(MAKE) -C examples/afl_network_proxy $(MAKE) -C examples/socket_fuzzing $(MAKE) -C examples/argv_fuzzing cd qemu_mode && sh ./build_qemu_support.sh @@ -476,6 +478,7 @@ distrib: all radamsa binary-only: all radamsa $(MAKE) -C libdislocator $(MAKE) -C libtokencap + $(MAKE) -C examples/afl_network_proxy $(MAKE) -C examples/socket_fuzzing $(MAKE) -C examples/argv_fuzzing cd qemu_mode && sh ./build_qemu_support.sh @@ -486,6 +489,9 @@ source-only: all radamsa -$(MAKE) -C gcc_plugin $(MAKE) -C libdislocator $(MAKE) -C libtokencap + #$(MAKE) -C examples/afl_network_proxy + #$(MAKE) -C examples/socket_fuzzing + #$(MAKE) -C examples/argv_fuzzing %.8: % @echo .TH $* 8 $(BUILD_DATE) "afl++" > $@ @@ -521,6 +527,7 @@ install: all $(MANPAGES) if [ -f afl-fuzz-document ]; then set -e; install -m 755 afl-fuzz-document $${DESTDIR}$(BIN_PATH); fi if [ -f socketfuzz32.so -o -f socketfuzz64.so ]; then $(MAKE) -C examples/socket_fuzzing install; fi if [ -f argvfuzz32.so -o -f argvfuzz64.so ]; then $(MAKE) -C examples/argv_fuzzing install; fi + if [ -f examples/afl_network_proxy/afl-network-server ]; then $(MAKE) -C examples/afl_network_proxy install; fi set -e; ln -sf afl-gcc $${DESTDIR}$(BIN_PATH)/afl-g++ set -e; if [ -f afl-clang-fast ] ; then ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang ; ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang++ ; else ln -sf afl-gcc $${DESTDIR}$(BIN_PATH)/afl-clang ; ln -sf afl-gcc $${DESTDIR}$(BIN_PATH)/afl-clang++; fi diff --git a/docs/Changelog.md b/docs/Changelog.md index dadfa7e0..565bee72 100644 --- a/docs/Changelog.md +++ b/docs/Changelog.md @@ -28,6 +28,13 @@ sending a mail to <afl-users+subscribe@googlegroups.com>. - unicorn_mode: - better submodule handling - afl-showmap: fix for -Q mode + - added examples/afl_network_proxy which allows to fuzz a target over the + network (not fuzzing tcp/ip services but running afl-fuzz on one system + and the target being on an embedded device) + - added examples/afl_untracer which does a binary-only fuzzing with the + modifications done in memory + - added examples/afl_proxy which can be easily used to fuzz and instrument + non-standard things - all: - forkserver communication now also used for error reporting - fix 32 bit build options diff --git a/examples/afl_network_proxy/Makefile b/examples/afl_network_proxy/Makefile new file mode 100644 index 00000000..eeee1178 --- /dev/null +++ b/examples/afl_network_proxy/Makefile @@ -0,0 +1,22 @@ +PREFIX ?= /usr/local +BIN_PATH = $(PREFIX)/bin +DOC_PATH = $(PREFIX)/share/doc/afl + +PROGRAMS = afl-network-client afl-network-server + +all: $(PROGRAMS) + +afl-network-client: afl-network-client.c + $(CC) -I../../include -o afl-network-client afl-network-client.c + +afl-network-server: afl-network-server.c + $(CC) -I../../include -o afl-network-server afl-network-server.c ../../src/afl-forkserver.c ../../src/afl-sharedmem.c ../../src/afl-common.c -DBIN_PATH=\"$(BIN_PATH)\" + +clean: + rm -f $(PROGRAMS) *~ core + +install: all + install -d -m 755 $${DESTDIR}$(BIN_PATH) $${DESTDIR}$(DOC_PATH) + install -m 755 $(PROGRAMS) $${DESTDIR}$(BIN_PATH) + install -m 644 README.md $${DESTDIR}$(DOC_PATH)/README.network_proxy.md + \ No newline at end of file diff --git a/examples/afl_network_proxy/README.md b/examples/afl_network_proxy/README.md new file mode 100644 index 00000000..c33096be --- /dev/null +++ b/examples/afl_network_proxy/README.md @@ -0,0 +1,55 @@ +# afl-network-proxy + +If you want to run afl-fuzz over the network than this is what you need :) +Note that the impact on fuzzing speed will be huge, expect a loss of 90%. + +## When to use this + +1. when you have to fuzz a target that has to run on a system that cannot + contain the fuzzing output (e.g. /tmp too small and file system is read-only) +2. when the target instantly reboots on crashes +3. ... any other reason you would need this + +## how to get it running + +### on the target + +Run `afl-network-server` with your target with the -m and -t values you need. +Important is the -i parameter which is the TCP port to liste on. +e.g.: +``` +$ afl-network-server -i 1111 -m 25M -t 1000 -- /bin/target -f @@ +``` + +### on the fuzzing master + +Just run afl-fuzz with your normal options, however the target should be +`afl-network-client` with the IP and PORT of the `afl-network-server` and +increase the -t value: +``` +$ afl-fuzz -i in -o out -t 2000+ -- afl-network-client TARGET-IP 1111 +``` +Note the '+' on the -t parameter value. the afl-network-server will take +care of proper timeouts hence afl-fuzz should not. The '+' increases the timout +and the value itself should be 500-1000 higher than the one on +afl-network-server. + +### networking + +The TARGET can be an IPv4 or IPv6 address, or a host name that resolves to +either. Note that also the outgoing interface can be specified with a '%' for +`afl-network-client`, e.g. `fe80::1234%eth0`. + +## how to compile and install + +`make && sudo make install` + +## Future + +It would be much faster and more effective if `afl-network-server` does not +send the map data back (64kb or more) but the checksum that `afl-fuzz` would +generate. This change however would make it incompatible with existing +afl spinoffs. + +But in the future this will be implemented and supported as a compile option. + diff --git a/examples/afl_network_proxy/afl-network-client.c b/examples/afl_network_proxy/afl-network-client.c new file mode 100644 index 00000000..b9cd88f0 --- /dev/null +++ b/examples/afl_network_proxy/afl-network-client.c @@ -0,0 +1,308 @@ +/* + american fuzzy lop++ - afl-network-client + --------------------------------------- + + Written by Marc Heuse <mh@mh-sec.de> + + Copyright 2019-2020 AFLplusplus Project. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + +*/ + +#ifdef __ANDROID__ +#include "android-ashmem.h" +#endif +#include "config.h" +#include "types.h" +#include "debug.h" + +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <unistd.h> +#include <string.h> +#include <assert.h> +#include <stdint.h> +#include <errno.h> + +#include <netinet/in.h> +#include <netinet/ip6.h> +#include <arpa/inet.h> +#include <sys/mman.h> +#include <sys/shm.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netdb.h> +#include <fcntl.h> + +u8 *__afl_area_ptr; + +#ifdef __ANDROID__ +u32 __afl_map_size = MAP_SIZE; +#else +__thread u32 __afl_map_size = MAP_SIZE; +#endif + +/* Error reporting to forkserver controller */ + +void send_forkserver_error(int error) { + + u32 status; + if (!error || error > 0xffff) return; + status = (FS_OPT_ERROR | FS_OPT_SET_ERROR(error)); + if (write(FORKSRV_FD + 1, (char *)&status, 4) != 4) return; + +} + +/* SHM setup. */ + +static void __afl_map_shm(void) { + + char *id_str = getenv(SHM_ENV_VAR); + char *ptr; + + if ((ptr = getenv("AFL_MAP_SIZE")) != NULL) { + + u32 val = atoi(ptr); + if (val > 0) __afl_map_size = val; + + } + + if (__afl_map_size > MAP_SIZE) { + + if (__afl_map_size > FS_OPT_MAX_MAPSIZE) { + + fprintf(stderr, + "Error: AFL++ tools *require* to set AFL_MAP_SIZE to %u to " + "be able to run this instrumented program!\n", + __afl_map_size); + if (id_str) { + + send_forkserver_error(FS_ERROR_MAP_SIZE); + exit(-1); + + } + + } else { + + fprintf(stderr, + "Warning: AFL++ tools will need to set AFL_MAP_SIZE to %u to " + "be able to run this instrumented program!\n", + __afl_map_size); + + } + + } + + if (id_str) { + +#ifdef USEMMAP + const char * shm_file_path = id_str; + int shm_fd = -1; + unsigned char *shm_base = NULL; + + /* create the shared memory segment as if it was a file */ + shm_fd = shm_open(shm_file_path, O_RDWR, 0600); + if (shm_fd == -1) { + + fprintf(stderr, "shm_open() failed\n"); + send_forkserver_error(FS_ERROR_SHM_OPEN); + exit(1); + + } + + /* map the shared memory segment to the address space of the process */ + shm_base = + mmap(0, __afl_map_size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); + + if (shm_base == MAP_FAILED) { + + close(shm_fd); + shm_fd = -1; + + fprintf(stderr, "mmap() failed\n"); + send_forkserver_error(FS_ERROR_MMAP); + exit(2); + + } + + __afl_area_ptr = shm_base; +#else + u32 shm_id = atoi(id_str); + + __afl_area_ptr = shmat(shm_id, 0, 0); + +#endif + + if (__afl_area_ptr == (void *)-1) { + + send_forkserver_error(FS_ERROR_SHMAT); + exit(1); + + } + + /* Write something into the bitmap so that the parent doesn't give up */ + + __afl_area_ptr[0] = 1; + + } + +} + +/* Fork server logic. */ + +static void __afl_start_forkserver(void) { + + u8 tmp[4] = {0, 0, 0, 0}; + u32 status = 0; + + if (__afl_map_size <= FS_OPT_MAX_MAPSIZE) + status |= (FS_OPT_SET_MAPSIZE(__afl_map_size) | FS_OPT_MAPSIZE); + if (status) status |= (FS_OPT_ENABLED); + memcpy(tmp, &status, 4); + + /* Phone home and tell the parent that we're OK. */ + + if (write(FORKSRV_FD + 1, tmp, 4) != 4) return; + +} + +static u32 __afl_next_testcase(u8 *buf, u32 max_len) { + + s32 status, res = 0x0fffffff; // res is a dummy pid + + /* Wait for parent by reading from the pipe. Abort if read fails. */ + if (read(FORKSRV_FD, &status, 4) != 4) return 0; + + /* we have a testcase - read it */ + status = read(0, buf, max_len); + + /* report that we are starting the target */ + if (write(FORKSRV_FD + 1, &res, 4) != 4) return 0; + + if (status < 1) + return 0; + else + return status; + +} + +static void __afl_end_testcase(int status) { + + if (write(FORKSRV_FD + 1, &status, 4) != 4) exit(1); + +} + +/* you just need to modify the while() loop in this main() */ + +int main(int argc, char *argv[]) { + + u8 * interface, *buf, *ptr; + s32 s = -1; + struct addrinfo hints, *hres, *aip; + u32 len, max_len = 65536; + + if (argc < 3 || argc > 4) { + + printf("Syntax: %s host port [max-input-size]\n\n", argv[0]); + printf("Requires host and port of the remote afl-proxy-server instance.\n"); + printf( + "IPv4 and IPv6 are supported, also binding to an interface with " + "\"%%\"\n"); + printf("The max-input-size default is %u.\n", max_len); + printf( + "The default map size is %u and can be changed with setting " + "AFL_MAP_SIZE.\n", + __afl_map_size); + exit(-1); + + } + + if ((interface = index(argv[1], '%')) != NULL) *interface++ = 0; + + if (argc > 3) + if ((max_len = atoi(argv[3])) < 0) + FATAL("max-input-size may not be negative or larger than 2GB: %s", + argv[3]); + + if ((ptr = getenv("AFL_MAP_SIZE")) != NULL) + if ((__afl_map_size = atoi(ptr)) < 8) + FATAL("illegal map size, may not be < 8 or >= 2^30: %s", ptr); + + if ((buf = malloc(max_len)) == NULL) + PFATAL("can not allocate %u memory", max_len); + + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_STREAM; + hints.ai_family = PF_UNSPEC; + + if (getaddrinfo(argv[1], argv[2], &hints, &hres) != 0) + PFATAL("could not resolve target %s", argv[1]); + + for (aip = hres; aip != NULL && s == -1; aip = aip->ai_next) { + + if ((s = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol)) >= 0) { + +#ifdef SO_BINDTODEVICE + if (interface != NULL) + if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, interface, + strlen(interface) + 1) < 0) + fprintf(stderr, "Warning: could not bind to device %s\n", interface); +#else + fprintf(stderr, + "Warning: binding to interface is not supported for your OS\n"); +#endif + if (connect(s, aip->ai_addr, aip->ai_addrlen) == -1) s = -1; + + } + + } + + if (s == -1) + FATAL("could not connect to target tcp://%s:%s", argv[1], argv[2]); + + /* we initialize the shared memory map and start the forkserver */ + __afl_map_shm(); + __afl_start_forkserver(); + + int i = 1, j, status, ret; + // fprintf(stderr, "Waiting for first testcase\n"); + while ((len = __afl_next_testcase(buf, max_len)) > 0) { + + // fprintf(stderr, "Sending testcase with len %u\n", len); + if (send(s, &len, 4, 0) != 4) PFATAL("sending size data %d failed", len); + if (send(s, buf, len, 0) != len) PFATAL("sending test data failed"); + + int received = 0; + while (received < 4 && + (ret = recv(s, &status + received, 4 - received, 0)) > 0) + received += ret; + if (received != 4) + FATAL("did not receive waitpid data (%d, %d)", received, ret); + // fprintf(stderr, "Received status\n"); + + received = 0; + while (received < __afl_map_size && + (ret = recv(s, __afl_area_ptr + received, __afl_map_size - received, + 0)) > 0) + received += ret; + if (received != __afl_map_size) + FATAL("did not receive coverage data (%d, %d)", received, ret); + // fprintf(stderr, "Received coverage\n"); + + /* report the test case is done and wait for the next */ + __afl_end_testcase(status); + // fprintf(stderr, "Waiting for next testcase %d\n", ++i); + + } + + return 0; + +} + diff --git a/examples/afl_network_proxy/afl-network-server.c b/examples/afl_network_proxy/afl-network-server.c new file mode 100644 index 00000000..e069af3d --- /dev/null +++ b/examples/afl_network_proxy/afl-network-server.c @@ -0,0 +1,604 @@ +/* + american fuzzy lop++ - network proxy server + ------------------------------------------- + + Originally written by Michal Zalewski + + Forkserver design by Jann Horn <jannhorn@googlemail.com> + + Now maintained by Marc Heuse <mh@mh-sec.de>, + Heiko Eißfeldt <heiko.eissfeldt@hexco.de> and + Andrea Fioraldi <andreafioraldi@gmail.com> and + Dominik Maier <mail@dmnk.co> + + Copyright 2016, 2017 Google Inc. All rights reserved. + Copyright 2019-2020 AFLplusplus Project. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + */ + +#define AFL_MAIN + +#ifdef __ANDROID__ +#include "android-ashmem.h" +#endif + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" +#include "hash.h" +#include "forkserver.h" +#include "sharedmem.h" +#include "common.h" + +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <errno.h> +#include <signal.h> +#include <dirent.h> +#include <fcntl.h> + +#include <sys/wait.h> +#include <sys/time.h> +#include <sys/shm.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/resource.h> +#include <netinet/in.h> +#include <netinet/ip6.h> +#include <arpa/inet.h> +#include <sys/mman.h> +#include <sys/shm.h> +#include <sys/socket.h> +#include <netdb.h> + +static u8 *in_file, /* Minimizer input test case */ + *out_file; + +static u8 *in_data; /* Input data for trimming */ + +static s32 in_len; +static u32 map_size = MAP_SIZE; + +static volatile u8 stop_soon; /* Ctrl-C pressed? */ + +/* See if any bytes are set in the bitmap. */ + +static inline u8 anything_set(afl_forkserver_t *fsrv) { + + u32 *ptr = (u32 *)fsrv->trace_bits; + u32 i = (map_size >> 2); + + while (i--) { + + if (*(ptr++)) { return 1; } + + } + + return 0; + +} + +static void at_exit_handler(void) { + + afl_fsrv_killall(); + +} + +/* Write output file. */ + +static s32 write_to_file(u8 *path, u8 *mem, u32 len) { + + s32 ret; + + unlink(path); /* Ignore errors */ + + ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600); + + if (ret < 0) { PFATAL("Unable to create '%s'", path); } + + ck_write(ret, mem, len, path); + + lseek(ret, 0, SEEK_SET); + + return ret; + +} + +/* Execute target application. Returns 0 if the changes are a dud, or + 1 if they should be kept. */ + +static u8 run_target(afl_forkserver_t *fsrv, char **argv, u8 *mem, u32 len, + u8 first_run) { + + afl_fsrv_write_to_testcase(fsrv, mem, len); + + fsrv_run_result_t ret = + afl_fsrv_run_target(fsrv, fsrv->exec_tmout, &stop_soon); + + if (ret == FSRV_RUN_ERROR) { FATAL("Couldn't run child"); } + + if (stop_soon) { + + SAYF(cRST cLRD "\n+++ aborted by user +++\n" cRST); + exit(1); + + } + +} + +/* Handle Ctrl-C and the like. */ + +static void handle_stop_sig(int sig) { + + stop_soon = 1; + afl_fsrv_killall(); + +} + +/* Do basic preparations - persistent fds, filenames, etc. */ + +static void set_up_environment(afl_forkserver_t *fsrv) { + + u8 *x; + + fsrv->dev_null_fd = open("/dev/null", O_RDWR); + if (fsrv->dev_null_fd < 0) { PFATAL("Unable to open /dev/null"); } + + if (!out_file) { + + u8 *use_dir = "."; + + if (access(use_dir, R_OK | W_OK | X_OK)) { + + use_dir = get_afl_env("TMPDIR"); + if (!use_dir) { use_dir = "/tmp"; } + + } + + out_file = alloc_printf("%s/.afl-input-temp-%u", use_dir, getpid()); + + } + + unlink(out_file); + + fsrv->out_fd = open(out_file, O_RDWR | O_CREAT | O_EXCL, 0600); + + if (fsrv->out_fd < 0) { PFATAL("Unable to create '%s'", out_file); } + + /* Set sane defaults... */ + + x = get_afl_env("ASAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "abort_on_error=1")) { + + FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!"); + + } + + if (!strstr(x, "symbolize=0")) { + + FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + } + + x = get_afl_env("MSAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR))) { + + FATAL("Custom MSAN_OPTIONS set without exit_code=" STRINGIFY( + MSAN_ERROR) " - please fix!"); + + } + + if (!strstr(x, "symbolize=0")) { + + FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + } + + setenv("ASAN_OPTIONS", + "abort_on_error=1:" + "detect_leaks=0:" + "symbolize=0:" + "allocator_may_return_null=1", + 0); + + setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" + "symbolize=0:" + "abort_on_error=1:" + "allocator_may_return_null=1:" + "msan_track_origins=0", 0); + + if (get_afl_env("AFL_PRELOAD")) { + + if (fsrv->qemu_mode) { + + u8 *qemu_preload = getenv("QEMU_SET_ENV"); + u8 *afl_preload = getenv("AFL_PRELOAD"); + u8 *buf; + + s32 i, afl_preload_size = strlen(afl_preload); + for (i = 0; i < afl_preload_size; ++i) { + + if (afl_preload[i] == ',') { + + PFATAL( + "Comma (',') is not allowed in AFL_PRELOAD when -Q is " + "specified!"); + + } + + } + + if (qemu_preload) { + + buf = alloc_printf("%s,LD_PRELOAD=%s,DYLD_INSERT_LIBRARIES=%s", + qemu_preload, afl_preload, afl_preload); + + } else { + + buf = alloc_printf("LD_PRELOAD=%s,DYLD_INSERT_LIBRARIES=%s", + afl_preload, afl_preload); + + } + + setenv("QEMU_SET_ENV", buf, 1); + + ck_free(buf); + + } else { + + setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1); + setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1); + + } + + } + +} + +/* Setup signal handlers, duh. */ + +static void setup_signal_handlers(void) { + + struct sigaction sa; + + sa.sa_handler = NULL; + sa.sa_flags = SA_RESTART; + sa.sa_sigaction = NULL; + + sigemptyset(&sa.sa_mask); + + /* Various ways of saying "stop". */ + + sa.sa_handler = handle_stop_sig; + sigaction(SIGHUP, &sa, NULL); + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + +} + +/* Display usage hints. */ + +static void usage(u8 *argv0) { + + SAYF( + "\n%s [ options ] -- /path/to/target_app [ ... ]\n\n" + + "Required parameters:\n" + + " -i port - the port to listen for the client to connect to\n\n" + + "Execution control settings:\n" + + " -f file - input file read by the tested program (stdin)\n" + " -t msec - timeout for each run (%d ms)\n" + " -m megs - memory limit for child process (%d MB)\n" + " -Q - use binary-only instrumentation (QEMU mode)\n" + " -U - use unicorn-based instrumentation (Unicorn mode)\n" + " -W - use qemu-based instrumentation with Wine (Wine " + "mode)\n\n" + + "Environment variables used:\n" + "TMPDIR: directory to use for temporary input files\n" + "ASAN_OPTIONS: custom settings for ASAN\n" + " (must contain abort_on_error=1 and symbolize=0)\n" + "MSAN_OPTIONS: custom settings for MSAN\n" + " (must contain exitcode="STRINGIFY(MSAN_ERROR)" and symbolize=0)\n" + "AFL_MAP_SIZE: the shared memory size for that target. must be >= the size\n" + " the target was compiled for\n" + "AFL_PRELOAD: LD_PRELOAD / DYLD_INSERT_LIBRARIES settings for target\n" + + , argv0, EXEC_TIMEOUT, MEM_LIMIT); + + exit(1); + +} + +int recv_testcase(int s, void **buf, size_t *max_len) { + + int size, received = 0, ret; + + while (received < 4 && (ret = recv(s, &size + received, 4 - received, 0)) > 0) + received += ret; + + if (received != 4) FATAL("did not receive size information"); + if (size < 1) FATAL("did not receive valid size information"); + // fprintf(stderr, "received size information of %d\n", size); + + *buf = maybe_grow(buf, max_len, size); + // fprintf(stderr, "receiving testcase %p %p max %u\n", buf, *buf, *max_len); + received = 0; + while (received < size && + (ret = recv(s, ((char *)*buf) + received, size - received, 0)) > 0) + received += ret; + + if (received != size) + FATAL("did not receive testcase data %u != %u, %d", received, size, ret); + + // fprintf(stderr, "received testcase\n"); + return size; + +} + +/* Main entry point */ + +int main(int argc, char **argv_orig, char **envp) { + + s32 opt, s, sock, on = 1, port = -1; + size_t max_len = 0; + u8 mem_limit_given = 0, timeout_given = 0, unicorn_mode = 0, use_wine = 0; + char **use_argv; + struct sockaddr_in6 serveraddr, clientaddr; + int addrlen = sizeof(clientaddr); + char str[INET6_ADDRSTRLEN]; + char ** argv = argv_cpy_dup(argc, argv_orig); + + afl_forkserver_t fsrv_var = {0}; + afl_forkserver_t *fsrv = &fsrv_var; + afl_fsrv_init(fsrv); + map_size = get_map_size(); + fsrv->map_size = map_size; + + while ((opt = getopt(argc, argv, "+i:f:m:t:QUWh")) > 0) { + + switch (opt) { + + case 'i': + + if (port > 0) { FATAL("Multiple -i options not supported"); } + port = atoi(optarg); + if (port < 1 || port > 65535) + FATAL("invalid port definition, must be between 1-65535: %s", optarg); + break; + + case 'f': + + if (out_file) { FATAL("Multiple -f options not supported"); } + fsrv->use_stdin = 0; + out_file = optarg; + break; + + case 'm': { + + u8 suffix = 'M'; + + if (mem_limit_given) { FATAL("Multiple -m options not supported"); } + mem_limit_given = 1; + + if (!optarg) { FATAL("Wrong usage of -m"); } + + if (!strcmp(optarg, "none")) { + + fsrv->mem_limit = 0; + break; + + } + + if (sscanf(optarg, "%llu%c", &fsrv->mem_limit, &suffix) < 1 || + optarg[0] == '-') { + + FATAL("Bad syntax used for -m"); + + } + + switch (suffix) { + + case 'T': + fsrv->mem_limit *= 1024 * 1024; + break; + case 'G': + fsrv->mem_limit *= 1024; + break; + case 'k': + fsrv->mem_limit /= 1024; + break; + case 'M': + break; + + default: + FATAL("Unsupported suffix or bad syntax for -m"); + + } + + if (fsrv->mem_limit < 5) { FATAL("Dangerously low value of -m"); } + + if (sizeof(rlim_t) == 4 && fsrv->mem_limit > 2000) { + + FATAL("Value of -m out of range on 32-bit systems"); + + } + + } + + break; + + case 't': + + if (timeout_given) { FATAL("Multiple -t options not supported"); } + timeout_given = 1; + + if (!optarg) { FATAL("Wrong usage of -t"); } + + fsrv->exec_tmout = atoi(optarg); + + if (fsrv->exec_tmout < 10 || optarg[0] == '-') { + + FATAL("Dangerously low value of -t"); + + } + + break; + + case 'Q': + + if (fsrv->qemu_mode) { FATAL("Multiple -Q options not supported"); } + if (!mem_limit_given) { fsrv->mem_limit = MEM_LIMIT_QEMU; } + + fsrv->qemu_mode = 1; + break; + + case 'U': + + if (unicorn_mode) { FATAL("Multiple -Q options not supported"); } + if (!mem_limit_given) { fsrv->mem_limit = MEM_LIMIT_UNICORN; } + + unicorn_mode = 1; + break; + + case 'W': /* Wine+QEMU mode */ + + if (use_wine) { FATAL("Multiple -W options not supported"); } + fsrv->qemu_mode = 1; + use_wine = 1; + + if (!mem_limit_given) { fsrv->mem_limit = 0; } + + break; + + case 'h': + usage(argv[0]); + return -1; + break; + + default: + usage(argv[0]); + + } + + } + + if (optind == argc || port < 1) { usage(argv[0]); } + + check_environment_vars(envp); + + sharedmem_t shm = {0}; + fsrv->trace_bits = afl_shm_init(&shm, map_size, 0); + + in_data = maybe_grow((void **)&in_data, &max_len, 65536); + + atexit(at_exit_handler); + setup_signal_handlers(); + + set_up_environment(fsrv); + + fsrv->target_path = find_binary(argv[optind]); + detect_file_args(argv + optind, out_file, &fsrv->use_stdin); + + if (fsrv->qemu_mode) { + + if (use_wine) { + + use_argv = get_wine_argv(argv[0], &fsrv->target_path, argc - optind, + argv + optind); + + } else { + + use_argv = get_qemu_argv(argv[0], &fsrv->target_path, argc - optind, + argv + optind); + + } + + } else { + + use_argv = argv + optind; + + } + + if ((sock = socket(AF_INET6, SOCK_STREAM, 0)) < 0) PFATAL("socket() failed"); + +#ifdef SO_REUSEADDR + if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)) < 0) { + + WARNF("setsockopt(SO_REUSEADDR) failed"); + + } + +#endif + memset(&serveraddr, 0, sizeof(serveraddr)); + serveraddr.sin6_family = AF_INET6; + serveraddr.sin6_port = htons(port); + serveraddr.sin6_addr = in6addr_any; + + if (bind(sock, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0) + PFATAL("bind() failed"); + + if (listen(sock, 1) < 0) { PFATAL("listen() failed"); } + + afl_fsrv_start(fsrv, use_argv, &stop_soon, + get_afl_env("AFL_DEBUG_CHILD_OUTPUT") ? 1 : 0); + + fprintf(stderr, + "Waiting for incoming connection from afl-network-client on port %d " + "...\n", + port); + + if ((s = accept(sock, NULL, NULL)) < 0) { PFATAL("accept() failed"); } + fprintf(stderr, "Received connection, starting ...\n"); + + while ((in_len = recv_testcase(s, (void **)&in_data, &max_len)) > 0) { + + // fprintf(stderr, "received %u\n", in_len); + run_target(fsrv, use_argv, in_data, in_len, 1); + + if (send(s, &fsrv->child_status, 4, 0) != 4) + FATAL("could not send waitpid data"); + if (send(s, fsrv->trace_bits, fsrv->map_size, 0) != fsrv->map_size) + FATAL("could not send coverage data"); + // fprintf(stderr, "sent result\n"); + + } + + unlink(out_file); + if (out_file) { ck_free(out_file); } + out_file = NULL; + + afl_shm_deinit(&shm); + afl_fsrv_deinit(fsrv); + if (fsrv->target_path) { ck_free(fsrv->target_path); } + if (in_data) { ck_free(in_data); } + + argv_cpy_free(argv); + + exit(0); + +} + diff --git a/examples/afl_proxy/Makefile b/examples/afl_proxy/Makefile new file mode 100644 index 00000000..4b368f8d --- /dev/null +++ b/examples/afl_proxy/Makefile @@ -0,0 +1,7 @@ +all: afl-proxy + +afl-proxy: afl-proxy.c + $(CC) -I../../include -o afl-proxy afl-proxy.c + +clean: + rm -f afl-proxy *~ core diff --git a/examples/afl_proxy/README.md b/examples/afl_proxy/README.md new file mode 100644 index 00000000..3c768a19 --- /dev/null +++ b/examples/afl_proxy/README.md @@ -0,0 +1,9 @@ +# afl-proxy + +afl-proxy is an example skeleton file which can easily be used to fuzz +and instrument non-standard things. + +You only need to change the while() loop of the main() to send the +data of buf[] with length len to the target and write the coverage +information to __afl_area_ptr[__afl_map_size] + diff --git a/examples/afl_proxy/afl-proxy.c b/examples/afl_proxy/afl-proxy.c new file mode 100644 index 00000000..36121e17 --- /dev/null +++ b/examples/afl_proxy/afl-proxy.c @@ -0,0 +1,238 @@ +/* + american fuzzy lop++ - afl-proxy skeleton example + --------------------------------------------------- + + Written by Marc Heuse <mh@mh-sec.de> + + Copyright 2019-2020 AFLplusplus Project. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + + HOW-TO + ====== + + You only need to change the while() loop of the main() to send the + data of buf[] with length len to the target and write the coverage + information to __afl_area_ptr[__afl_map_size] + + +*/ + +#ifdef __ANDROID__ +#include "android-ashmem.h" +#endif +#include "config.h" +#include "types.h" + +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <unistd.h> +#include <string.h> +#include <assert.h> +#include <stdint.h> +#include <errno.h> + +#include <sys/mman.h> +#include <sys/shm.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <fcntl.h> + +u8 *__afl_area_ptr; + +#ifdef __ANDROID__ +u32 __afl_map_size = MAP_SIZE; +#else +__thread u32 __afl_map_size = MAP_SIZE; +#endif + +/* Error reporting to forkserver controller */ + +void send_forkserver_error(int error) { + + u32 status; + if (!error || error > 0xffff) return; + status = (FS_OPT_ERROR | FS_OPT_SET_ERROR(error)); + if (write(FORKSRV_FD + 1, (char *)&status, 4) != 4) return; + +} + +/* SHM setup. */ + +static void __afl_map_shm(void) { + + char *id_str = getenv(SHM_ENV_VAR); + char *ptr; + + if ((ptr = getenv("AFL_MAP_SIZE")) != NULL) { + + u32 val = atoi(ptr); + if (val > 0) __afl_map_size = val; + + } + + if (__afl_map_size > MAP_SIZE) { + + if (__afl_map_size > FS_OPT_MAX_MAPSIZE) { + + fprintf(stderr, + "Error: AFL++ tools *require* to set AFL_MAP_SIZE to %u to " + "be able to run this instrumented program!\n", + __afl_map_size); + if (id_str) { + + send_forkserver_error(FS_ERROR_MAP_SIZE); + exit(-1); + + } + + } else { + + fprintf(stderr, + "Warning: AFL++ tools will need to set AFL_MAP_SIZE to %u to " + "be able to run this instrumented program!\n", + __afl_map_size); + + } + + } + + if (id_str) { + +#ifdef USEMMAP + const char * shm_file_path = id_str; + int shm_fd = -1; + unsigned char *shm_base = NULL; + + /* create the shared memory segment as if it was a file */ + shm_fd = shm_open(shm_file_path, O_RDWR, 0600); + if (shm_fd == -1) { + + fprintf(stderr, "shm_open() failed\n"); + send_forkserver_error(FS_ERROR_SHM_OPEN); + exit(1); + + } + + /* map the shared memory segment to the address space of the process */ + shm_base = + mmap(0, __afl_map_size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); + + if (shm_base == MAP_FAILED) { + + close(shm_fd); + shm_fd = -1; + + fprintf(stderr, "mmap() failed\n"); + send_forkserver_error(FS_ERROR_MMAP); + exit(2); + + } + + __afl_area_ptr = shm_base; +#else + u32 shm_id = atoi(id_str); + + __afl_area_ptr = shmat(shm_id, 0, 0); + +#endif + + if (__afl_area_ptr == (void *)-1) { + + send_forkserver_error(FS_ERROR_SHMAT); + exit(1); + + } + + /* Write something into the bitmap so that the parent doesn't give up */ + + __afl_area_ptr[0] = 1; + + } + +} + +/* Fork server logic. */ + +static void __afl_start_forkserver(void) { + + u8 tmp[4] = {0, 0, 0, 0}; + u32 status = 0; + + if (__afl_map_size <= FS_OPT_MAX_MAPSIZE) + status |= (FS_OPT_SET_MAPSIZE(__afl_map_size) | FS_OPT_MAPSIZE); + if (status) status |= (FS_OPT_ENABLED); + memcpy(tmp, &status, 4); + + /* Phone home and tell the parent that we're OK. */ + + if (write(FORKSRV_FD + 1, tmp, 4) != 4) return; + +} + +static u32 __afl_next_testcase(u8 *buf, u32 max_len) { + + s32 status, res = 0xffffff; + + /* Wait for parent by reading from the pipe. Abort if read fails. */ + if (read(FORKSRV_FD, &status, 4) != 4) return 0; + + /* we have a testcase - read it */ + status = read(0, buf, max_len); + + /* report that we are starting the target */ + if (write(FORKSRV_FD + 1, &res, 4) != 4) return 0; + + if (status < 1) + return 0; + else + return status; + +} + +static void __afl_end_testcase(void) { + + int status = 0xffffff; + + if (write(FORKSRV_FD + 1, &status, 4) != 4) exit(1); + +} + +/* you just need to modify the while() loop in this main() */ + +int main(int argc, char *argv[]) { + + /* This is were the testcase data is written into */ + u8 buf[1024]; // this is the maximum size for a test case! set it! + u32 len; + + /* here you specify the map size you need that you are reporting to + afl-fuzz. */ + __afl_map_size = MAP_SIZE; // default is 65536 + + /* then we initialize the shared memory map and start the forkserver */ + __afl_map_shm(); + __afl_start_forkserver(); + + while ((len = __afl_next_testcase(buf, sizeof(buf))) > 0) { + + /* here you have to create the magic that feeds the buf/len to the + target and write the coverage to __afl_area_ptr */ + + // ... the magic ... + + /* report the test case is done and wait for the next */ + __afl_end_testcase(); + + } + + return 0; + +} + diff --git a/examples/afl_untracer/Makefile b/examples/afl_untracer/Makefile new file mode 100644 index 00000000..5c525877 --- /dev/null +++ b/examples/afl_untracer/Makefile @@ -0,0 +1,10 @@ +all: afl-untracer libtestinstr.so + +afl-untracer: afl-untracer.c + $(CC) -I../../include -g -o afl-untracer afl-untracer.c -ldl -pthread + +libtestinstr.so: libtestinstr.c + $(CC) -fPIC -o libtestinstr.so -shared libtestinstr.c + +clean: + rm -f afl-untracer libtestinstr.so *~ core diff --git a/examples/afl_untracer/README.md b/examples/afl_untracer/README.md new file mode 100644 index 00000000..d3af0ceb --- /dev/null +++ b/examples/afl_untracer/README.md @@ -0,0 +1,16 @@ +# afl-untracer + +afl-untracer is an example skeleton file which can easily be used to fuzz +a closed source library. + +It requires less memory than qemu_mode however it is way +more course grained and does not provide interesting features like compcov +or cmplog. + +Read and modify afl-untracer.c then `make` and use it as the afl-fuzz target +(or even remote via afl-network-proxy). + +This idea is based on [UnTracer](https://github.com/FoRTE-Research/UnTracer-AFL) +and modified by [Trapfuzz](https://github.com/googleprojectzero/p0tools/tree/master/TrapFuzz). +This implementation is slower because the traps are not patched out with each +run, but on the other hand gives much better coverage information. diff --git a/examples/afl_untracer/afl-untracer.c b/examples/afl_untracer/afl-untracer.c new file mode 100644 index 00000000..5338bfd5 --- /dev/null +++ b/examples/afl_untracer/afl-untracer.c @@ -0,0 +1,709 @@ +/* + american fuzzy lop++ - afl-untracer skeleton example + --------------------------------------------------- + + Written by Marc Heuse <mh@mh-sec.de> + + Copyright 2019-2020 AFLplusplus Project. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + + HOW-TO + ====== + + You only need to change the following: + + 1. decide if you want to receive data from stdin [DEFAULT] or file(name) + -> use_stdin = 0 if via file, and what the maximum input size is + 2. dl load the library you want to fuzz, lookup the functions you need + and setup the calls to these + 3. in the while loop you call the functions in the necessary order - + incl the cleanup. the cleanup is important! + + Just look these steps up in the code, look for "// STEP x:" + + +*/ + +#define __USE_GNU +#define _GNU_SOURCE + +#ifdef __ANDROID__ +#include "android-ashmem.h" +#endif +#include "config.h" +#include "types.h" +#include "debug.h" + +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <unistd.h> +#include <string.h> +#include <assert.h> +#include <stdint.h> +#include <errno.h> +#include <dlfcn.h> +#include <fcntl.h> +#include <pthread.h> + +#include <sys/mman.h> +#include <sys/shm.h> +#include <sys/wait.h> +#include <sys/types.h> + +#if defined(__linux__) +#include <sys/ucontext.h> +#elif defined(__APPLE__) && defined(__LP64__) +#include <mach-o/dyld_images.h> +#elif defined(__FreeBSD__) +#include <sys/sysctl.h> +#include <sys/user.h> +#else +#error "Unsupproted platform" +#endif + +#define MEMORY_MAP_DECREMENT 0x200000000000 +#define MAX_LIB_COUNT 128 + +// STEP 1: + +/* use stdin (1) or a file on the commandline (0) */ +static u32 use_stdin = 1; + +/* This is were the testcase data is written into */ +static u8 buf[10000]; // this is the maximum size for a test case! set it! + +/* If you want to have debug output set this to 1, can also be set with + AFL_DEBUG */ +static u32 debug = 0; + +// END STEP 1 + +typedef struct library_list { + + u8 *name; + u64 addr_start, addr_end; + +} library_list_t; + +#ifdef __ANDROID__ +u32 __afl_map_size = MAP_SIZE; +u32 do_exit; +#else +__thread u32 __afl_map_size = MAP_SIZE; +__thread u32 do_exit; +#endif + +static pid_t pid = 65537; +static pthread_t __afl_thread; +static u8 __afl_dummy[MAP_SIZE]; +static u8 * __afl_area_ptr = __afl_dummy; +static u8 * inputfile; // this will point to argv[1] +static u32 len; + +static library_list_t liblist[MAX_LIB_COUNT]; +static u32 liblist_cnt; + +static void sigtrap_handler(int signum, siginfo_t *si, void *context); +static void fuzz(); + +/* read the library information */ +void read_library_information() { + +#if defined(__linux__) + FILE *f; + u8 buf[1024], *b, *m, *e, *n; + + if ((f = fopen("/proc/self/maps", "r")) == NULL) + FATAL("cannot open /proc/self/maps"); + + if (debug) fprintf(stderr, "Library list:\n"); + while (fgets(buf, sizeof(buf), f)) { + + if (strstr(buf, " r-x")) { + + if (liblist_cnt >= MAX_LIB_COUNT) { + + WARNF("too many libraries to old, maximum count of %d reached", + liblist_cnt); + return; + + } + + b = buf; + m = index(buf, '-'); + e = index(buf, ' '); + if ((n = rindex(buf, '/')) == NULL) n = rindex(buf, ' '); + if (n && + ((*n >= '0' && *n <= '9') || *n == '[' || *n == '{' || *n == '(')) + n = NULL; + else + n++; + if (b && m && e && n && *n) { + + *m++ = 0; + *e = 0; + if (n[strlen(n) - 1] == '\n') n[strlen(n) - 1] = 0; + + liblist[liblist_cnt].name = strdup(n); + liblist[liblist_cnt].addr_start = strtoull(b, NULL, 16); + liblist[liblist_cnt].addr_end = strtoull(m, NULL, 16); + if (debug) + fprintf( + stderr, "%s:%x (%lx-%lx)\n", liblist[liblist_cnt].name, + liblist[liblist_cnt].addr_end - liblist[liblist_cnt].addr_start, + liblist[liblist_cnt].addr_start, + liblist[liblist_cnt].addr_end - 1); + liblist_cnt++; + + } + + } + + } + + if (debug) fprintf(stderr, "\n"); + +#elif defined(__FreeBSD__) + int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, getpid()}; + char * buf, *start, *end; + size_t miblen = sizeof(mib) / sizeof(mib[0]); + size_t len; + + if (debug) fprintf(stderr, "Library list:\n"); + if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) { return; } + + len = len * 4 / 3; + + buf = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0); + if (buf == MAP_FAILED) { return; } + + if (sysctl(mib, miblen, buf, &len, NULL, 0) == -1) { + + munmap(buf, len); + return; + + } + + start = buf; + end = buf + len; + + while (start < end) { + + struct kinfo_vmentry *region = (struct kinfo_vmentry *)start; + size_t size = region->kve_structsize; + + if (size == 0) { break; } + + if ((region->kve_protection & KVME_PROT_READ) && + !(region->kve_protection & KVME_PROT_EXEC)) { + + liblist[liblist_cnt].name = + region->kve_path[0] != '\0' ? strdup(region->kve_path) : 0; + liblist[liblist_cnt].addr_start = region->kve_start; + liblist[liblist_cnt].addr_end = region->kve_end; + + if (debug) { + + fprintf(stderr, "%s:%x (%lx-%lx)\n", liblist[liblist_cnt].name, + liblist[liblist_cnt].addr_end - liblist[liblist_cnt].addr_start, + liblist[liblist_cnt].addr_start, + liblist[liblist_cnt].addr_end - 1); + + } + + liblist_cnt++; + + } + + start += size; + + } + +#endif + +} + +library_list_t *find_library(char *name) { + +#if defined(__linux__) + u32 i; + + for (i = 0; i < liblist_cnt; i++) + if (strncmp(liblist[i].name, name, strlen(name)) == 0) return &liblist[i]; +#elif defined(__APPLE__) && defined(__LP64__) + kern_return_t err; + static library_list_t lib; + + // get the list of all loaded modules from dyld + // the task_info mach API will get the address of the dyld all_image_info + // struct for the given task from which we can get the names and load + // addresses of all modules + task_dyld_info_data_t task_dyld_info; + mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT; + err = task_info(mach_task_self(), TASK_DYLD_INFO, + (task_info_t)&task_dyld_info, &count); + + const struct dyld_all_image_infos *all_image_infos = + (const struct dyld_all_image_infos *)task_dyld_info.all_image_info_addr; + const struct dyld_image_info *image_infos = all_image_infos->infoArray; + + for (size_t i = 0; i < all_image_infos->infoArrayCount; i++) { + + const char * image_name = image_infos[i].imageFilePath; + mach_vm_address_t image_load_address = + (mach_vm_address_t)image_infos[i].imageLoadAddress; + if (strstr(image_name, name)) { + + lib.name = name; + lib.addr_start = (u64)image_load_address; + lib.addr_end = 0; + return &lib; + + } + + } + +#endif + + return NULL; + +} + +/* Error reporting to forkserver controller */ + +void send_forkserver_error(int error) { + + u32 status; + if (!error || error > 0xffff) return; + status = (FS_OPT_ERROR | FS_OPT_SET_ERROR(error)); + if (write(FORKSRV_FD + 1, (char *)&status, 4) != 4) return; + +} + +/* SHM setup. */ + +static void __afl_map_shm(void) { + + char *id_str = getenv(SHM_ENV_VAR); + char *ptr; + + if ((ptr = getenv("AFL_MAP_SIZE")) != NULL) { + + u32 val = atoi(ptr); + if (val > 0) __afl_map_size = val; + + } + + if (__afl_map_size > MAP_SIZE) { + + if (__afl_map_size > FS_OPT_MAX_MAPSIZE) { + + fprintf(stderr, + "Error: AFL++ tools *require* to set AFL_MAP_SIZE to %u to " + "be able to run this instrumented program!\n", + __afl_map_size); + if (id_str) { + + send_forkserver_error(FS_ERROR_MAP_SIZE); + exit(-1); + + } + + } else { + + fprintf(stderr, + "Warning: AFL++ tools will need to set AFL_MAP_SIZE to %u to " + "be able to run this instrumented program!\n", + __afl_map_size); + + } + + } + + if (id_str) { + +#ifdef USEMMAP + const char * shm_file_path = id_str; + int shm_fd = -1; + unsigned char *shm_base = NULL; + + /* create the shared memory segment as if it was a file */ + shm_fd = shm_open(shm_file_path, O_RDWR, 0600); + if (shm_fd == -1) { + + fprintf(stderr, "shm_open() failed\n"); + send_forkserver_error(FS_ERROR_SHM_OPEN); + exit(1); + + } + + /* map the shared memory segment to the address space of the process */ + shm_base = + mmap(0, __afl_map_size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); + + if (shm_base == MAP_FAILED) { + + close(shm_fd); + shm_fd = -1; + + fprintf(stderr, "mmap() failed\n"); + send_forkserver_error(FS_ERROR_MMAP); + exit(2); + + } + + __afl_area_ptr = shm_base; +#else + u32 shm_id = atoi(id_str); + + __afl_area_ptr = shmat(shm_id, 0, 0); + +#endif + + if (__afl_area_ptr == (void *)-1) { + + send_forkserver_error(FS_ERROR_SHMAT); + exit(1); + + } + + /* Write something into the bitmap so that the parent doesn't give up */ + + __afl_area_ptr[0] = 1; + + } + +} + +/* Fork server logic. */ +static void __afl_start_forkserver(void) { + + u8 tmp[4] = {0, 0, 0, 0}; + u32 status = 0; + + if (__afl_map_size <= FS_OPT_MAX_MAPSIZE) + status |= (FS_OPT_SET_MAPSIZE(__afl_map_size) | FS_OPT_MAPSIZE); + if (status) status |= (FS_OPT_ENABLED); + memcpy(tmp, &status, 4); + + /* Phone home and tell the parent that we're OK. */ + if (write(FORKSRV_FD + 1, tmp, 4) != 4) do_exit = 1; + // fprintf(stderr, "write0 %d\n", do_exit); + +} + +static u32 __afl_next_testcase(u8 *buf, u32 max_len) { + + s32 status; + + /* Wait for parent by reading from the pipe. Abort if read fails. */ + if (read(FORKSRV_FD, &status, 4) != 4) do_exit = 1; + // fprintf(stderr, "read %d\n", do_exit); + + /* we have a testcase - read it if we read from stdin */ + if (use_stdin) { + + if ((status = read(0, buf, max_len)) <= 0) exit(-1); + + } else + + status = 1; + // fprintf(stderr, "stdin: %d %d\n", use_stdin, status); + + /* report that we are starting the target */ + if (write(FORKSRV_FD + 1, &pid, 4) != 4) do_exit = 1; + // fprintf(stderr, "write1 %d\n", do_exit); + + return status; + +} + +static void __afl_end_testcase(int status) { + + if (write(FORKSRV_FD + 1, &status, 4) != 4) do_exit = 1; + // fprintf(stderr, "write2 %d\n", do_exit); + if (do_exit) exit(0); + +} + +#define SHADOW(addr) \ + ((uint32_t *)(((uintptr_t)addr & 0xfffffffffffffffc) - \ + MEMORY_MAP_DECREMENT - \ + ((uintptr_t)addr & 0x3) * 0x10000000000)) + +void setup_trap_instrumentation() { + + library_list_t *lib_base = NULL; + size_t lib_size = 0; + u8 * lib_addr; + char * line = NULL; + size_t nread, len = 0; + char * filename = getenv("AFL_UNTRACER_FILE"); + if (!filename) filename = getenv("TRAPFUZZ_FILE"); + if (!filename) FATAL("AFL_UNTRACER_FILE environment variable not set"); + + FILE *patches = fopen(filename, "r"); + if (!patches) FATAL("Couldn't open AFL_UNTRACER_FILE file %s", filename); + + // Index into the coverage bitmap for the current trap instruction. + int bitmap_index = 0; + + while ((nread = getline(&line, &len, patches)) != -1) { + + char *end = line + len; + + char *col = strchr(line, ':'); + if (col) { + + // It's a library:size pair + *col++ = 0; + + lib_base = find_library(line); + if (!lib_base) FATAL("Library %s does not appear to be loaded", line); + + // we ignore the defined lib_size + lib_size = strtoul(col, NULL, 16); +#if (__linux__) + if (lib_size < lib_base->addr_end - lib_base->addr_start) + lib_size = lib_base->addr_end - lib_base->addr_start; +#endif + if (lib_size % 0x1000 != 0) + WARNF("Invalid library size 0x%zx. Must be multiple of 0x1000", + lib_size); + + lib_addr = (u8 *)lib_base->addr_start; + + // Make library code writable. + if (mprotect((void *)lib_addr, lib_size, + PROT_READ | PROT_WRITE | PROT_EXEC) != 0) + FATAL("Failed to mprotect library %s writable", line); + + // Create shadow memory. + for (int i = 0; i < 4; i++) { + + void *shadow_addr = SHADOW(lib_addr + i); + void *shadow = mmap(shadow_addr, lib_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON | MAP_FIXED, 0, 0); + if (debug) + fprintf(stderr, "Shadow: %s %d = %p-%p for %p\n", line, i, shadow, + shadow + lib_size - 1, lib_addr); + if (shadow == MAP_FAILED) FATAL("Failed to mmap shadow memory"); + + } + + // Done, continue with next line. + continue; + + } + + // It's an offset, parse it and do the patching. + unsigned long offset = strtoul(line, NULL, 16); + + // I dont know what it is. /proc/<pid>/maps shows the right start address + // and the offsets generated by the python scripts are fine as well. + // And loading the library into gdb also shows the offsets generated + // by the script are correct. However when loaded via dlopen the first + // 0x1000 are skipped ... +#if defined(__linux__) + if (offset >= 0x1000) + offset -= 0x1000; + else + fprintf(stderr, "Warning: offset is < 0x1000: %x\n", offset); +#endif + + if (offset > lib_size) + FATAL("Invalid offset: 0x%lx. Current library is 0x%zx bytes large", + offset, lib_size); + + if (bitmap_index >= __afl_map_size) + FATAL("Too many basic blocks to instrument"); + + uint32_t *shadow = SHADOW(lib_addr + offset); + if (*shadow != 0) FATAL("Duplicate patch entry: 0x%lx", offset); + + // Make lookup entry in shadow memory. +#if ((defined(__APPLE__) && defined(__LP64__)) || defined(__x86_64__)) + // this is for Intel x64 + + uint8_t orig_byte = lib_addr[offset]; + *shadow = (bitmap_index << 8) | orig_byte; + lib_addr[offset] = 0xcc; // replace instruction with debug trap + if (debug) + fprintf(stderr, + "Patch entry: %p[%x] = %p = %02x -> SHADOW(%p) #%d -> %08x\n", + lib_addr, offset, lib_addr + offset, orig_byte, shadow, + bitmap_index, *shadow); + +#else + // this will be ARM and AARCH64 + // for ARM we will need to identify if the code is in thumb or ARM +#error "non x86_64 not supported yet" + //__arm__: + // linux thumb: 0xde01 + // linux arm: 0xe7f001f0 + //__aarch64__: + // linux aarch64: 0xd4200000 +#endif + + bitmap_index++; + + } + + free(line); + fclose(patches); + + // Install signal handler for SIGTRAP. + struct sigaction s; + s.sa_flags = SA_SIGINFO; + s.sa_sigaction = sigtrap_handler; + sigemptyset(&s.sa_mask); + sigaction(SIGTRAP, &s, 0); + + if (debug) fprintf(stderr, "Patched %u locations.\n", bitmap_index); + __afl_map_size = bitmap_index; + if (__afl_map_size % 8) __afl_map_size = (((__afl_map_size + 7) >> 3) << 3); + +} + +/* the signal handler for the traps / debugging interrupts + No debug output here because this would cost speed */ +static void sigtrap_handler(int signum, siginfo_t *si, void *context) { + + uint64_t addr; + // Must re-execute the instruction, so decrement PC by one instruction. + ucontext_t *ctx = (ucontext_t *)context; +#if defined(__APPLE__) && defined(__LP64__) + ctx->uc_mcontext->__ss.__rip -= 1; + addr = ctx->uc_mcontext->__ss.__rip; +#elif defined(__linux__) + ctx->uc_mcontext.gregs[REG_RIP] -= 1; + addr = ctx->uc_mcontext.gregs[REG_RIP]; +#elif defined(__FreeBSD__) && defined(__LP64__) + ctx->uc_mcontext.mc_rip -= 1; + addr = ctx->uc_mcontext.mc_rip; +#else +#error "Unsupported platform" +#endif + + // fprintf(stderr, "TRAP at context addr = %lx, fault addr = %lx\n", addr, + // si->si_addr); + + // If the trap didn't come from our instrumentation, then we probably will + // just segfault here + uint8_t *faultaddr; + if (unlikely(si->si_addr)) + faultaddr = (u8 *)si->si_addr - 1; + else + faultaddr = (u8 *)addr; + // if (debug) fprintf(stderr, "Shadow location: %p\n", SHADOW(faultaddr)); + uint32_t shadow = *SHADOW(faultaddr); + uint8_t orig_byte = shadow & 0xff; + uint32_t index = shadow >> 8; + + // if (debug) fprintf(stderr, "shadow data: %x, orig_byte %02x, index %d\n", + // shadow, orig_byte, index); + + // Index zero is invalid so that it is still possible to catch actual trap + // instructions in instrumented libraries. + if (unlikely(index == 0)) abort(); + + // Restore original instruction + *faultaddr = orig_byte; + + __afl_area_ptr[index] = 128; + +} + +/* here you need to specify the parameter for the target function */ +static void *(*o_function)(u8 *buf, int len); + +/* the MAIN function */ +int main(int argc, char *argv[]) { + + pid = getpid(); + if (getenv("AFL_DEBUG")) debug = 1; + + /* by default we use stdin, but also a filename can be passed, in this + case the input is argv[1] and we have to disable stdin */ + if (argc > 1) { + + use_stdin = 0; + inputfile = argv[1]; + + } + + // STEP 2: load the library you want to fuzz and lookup the functions, + // inclusive of the cleanup functions + // NOTE: above the main() you have to define the functions! + + void *dl = dlopen("./libtestinstr.so", RTLD_LAZY); + if (!dl) FATAL("could not find target library"); + o_function = dlsym(dl, "testinstr"); + if (!o_function) FATAL("could not resolve target function from library"); + if (debug) fprintf(stderr, "Function address: %p\n", o_function); + + // END STEP 2 + + /* setup instrumentation, shared memory and forkserver */ + read_library_information(); + setup_trap_instrumentation(); + __afl_map_shm(); + __afl_start_forkserver(); + + while (1) { + + if ((pid = fork()) == -1) PFATAL("fork failed"); + + if (pid) { + + u32 status; + if (waitpid(pid, &status, 0) < 0) exit(1); + /* report the test case is done and wait for the next */ + __afl_end_testcase(status); + + } else { + + pid = getpid(); + while ((len = __afl_next_testcase(buf, sizeof(buf))) > 0) { + + // in this function the fuzz magic happens, this is STEP 3 + fuzz(); + + // we can use _exit which is faster because our target library + // was loaded via dlopen and there cannot have deconstructors + // registered. + _exit(0); + + } + + } + + } + + return 0; + +} + +static void fuzz() { + + // STEP 3: call the function to fuzz, also the functions you might + // need to call to prepare the function and - important! - + // to clean everything up + + // in this example we use the input file, not stdin! + (*o_function)(buf, len); + + // normally you also need to cleanup + //(*o_LibFree)(foo); + + // END STEP 3 + +} + diff --git a/examples/afl_untracer/ida_get_patchpoints.py b/examples/afl_untracer/ida_get_patchpoints.py new file mode 100644 index 00000000..5a79658d --- /dev/null +++ b/examples/afl_untracer/ida_get_patchpoints.py @@ -0,0 +1,52 @@ +# +# IDAPython script for IDA Pro +# Slightly modified from https://github.com/googleprojectzero/p0tools/blob/master/TrapFuzz/findPatchPoints.py +# + +import idautils +import idaapi +import ida_nalt +import idc + +# See https://www.hex-rays.com/products/ida/support/ida74_idapython_no_bc695_porting_guide.shtml + +from os.path import expanduser +home = expanduser("~") + +patchpoints = set() + +max_offset = 0 +for seg_ea in idautils.Segments(): + name = idc.get_segm_name(seg_ea) + #print("Segment: " + name) + if name != "__text" and name != ".text": + continue + + start = idc.get_segm_start(seg_ea) + end = idc.get_segm_end(seg_ea) + #print("Start: " + hex(start) + " End: " + hex(end)) + for func_ea in idautils.Functions(start, end): + f = idaapi.get_func(func_ea) + if not f: + continue + for block in idaapi.FlowChart(f): + if start <= block.start_ea < end: + max_offset = max(max_offset, block.start_ea) + patchpoints.add(block.start_ea) + #else: + # print("Warning: broken CFG?") + +# Round up max_offset to page size +size = max_offset +rem = size % 0x1000 +if rem != 0: + size += 0x1000 - rem + +print("Writing to " + home + "/Desktop/patches.txt") + +with open(home + "/Desktop/patches.txt", "w") as f: + f.write(ida_nalt.get_root_filename() + ':' + hex(size) + '\n') + f.write('\n'.join(map(hex, sorted(patchpoints)))) + f.write('\n') + +print("Done, found {} patchpoints".format(len(patchpoints))) diff --git a/examples/afl_untracer/libtestinstr.c b/examples/afl_untracer/libtestinstr.c new file mode 100644 index 00000000..96b1cf21 --- /dev/null +++ b/examples/afl_untracer/libtestinstr.c @@ -0,0 +1,35 @@ +/* + american fuzzy lop++ - a trivial program to test the build + -------------------------------------------------------- + Originally written by Michal Zalewski + Copyright 2014 Google Inc. All rights reserved. + Copyright 2019-2020 AFLplusplus Project. All rights reserved. + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + http://www.apache.org/licenses/LICENSE-2.0 + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +void testinstr(char *buf, int len) { + + if (len < 1) return; + buf[len] = 0; + + // we support three input cases + if (buf[0] == '0') + printf("Looks like a zero to me!\n"); + else if (buf[0] == '1') + printf("Pretty sure that is a one!\n"); + else + printf("Neither one or zero? How quaint!\n"); + +} + diff --git a/examples/afl_untracer/patches.txt b/examples/afl_untracer/patches.txt new file mode 100644 index 00000000..b3063e3a --- /dev/null +++ b/examples/afl_untracer/patches.txt @@ -0,0 +1,23 @@ +libtestinstr.so:0x2000L +0x1050L +0x1063L +0x106fL +0x1078L +0x1080L +0x10a4L +0x10b0L +0x10b8L +0x10c0L +0x10c9L +0x10d7L +0x10e3L +0x10f8L +0x1100L +0x1105L +0x111aL +0x1135L +0x1143L +0x114eL +0x115cL +0x116aL +0x116bL diff --git a/include/forkserver.h b/include/forkserver.h index 3c473572..7e7784f5 100644 --- a/include/forkserver.h +++ b/include/forkserver.h @@ -43,6 +43,7 @@ typedef struct afl_forkserver { s32 fsrv_pid, /* PID of the fork server */ child_pid, /* PID of the fuzzed program */ + child_status, /* waitpid result for the child */ out_dir_fd; /* FD of the lock file */ s32 out_fd, /* Persistent fd for fsrv->out_file */ diff --git a/llvm_mode/GNUmakefile b/llvm_mode/GNUmakefile index 69b0875e..2cbe53cd 100644 --- a/llvm_mode/GNUmakefile +++ b/llvm_mode/GNUmakefile @@ -38,7 +38,7 @@ else LLVM_CONFIG ?= llvm-config endif -LLVMVER = $(shell $(LLVM_CONFIG) --version 2>/dev/null ) +LLVMVER = $(shell $(LLVM_CONFIG) --version 2>/dev/null | sed 's/git//' ) LLVM_UNSUPPORTED = $(shell $(LLVM_CONFIG) --version 2>/dev/null | egrep -q '^3\.[0-7]|^1[2-9]' && echo 1 || echo 0 ) LLVM_NEW_API = $(shell $(LLVM_CONFIG) --version 2>/dev/null | egrep -q '^1[0-9]' && echo 1 || echo 0 ) LLVM_MAJOR = $(shell $(LLVM_CONFIG) --version 2>/dev/null | sed 's/\..*//') @@ -82,30 +82,66 @@ endif # this seems to be busted on some distros, so using the one in $PATH is # probably better. -CC ?= $(LLVM_BINDIR)/clang -CXX ?= $(LLVM_BINDIR)/clang++ +CC = $(LLVM_BINDIR)/clang +CXX = $(LLVM_BINDIR)/clang++ +# llvm-config --bindir may not providing a valid path, so ... ifeq "$(shell test -e $(CC) || echo 1 )" "1" - # llvm-config --bindir may not providing a valid path, so ... - ifeq "$(shell test -e '$(BIN_DIR)/clang' && echo 1)" "1" - # we found one in the local install directory, lets use these - CC = $(BIN_DIR)/clang - CXX = $(BIN_DIR)/clang++ - else - # hope for the best - $(warning we have trouble finding clang/clang++ - llvm-config is not helping us) - CC = clang - CXX = clang++ + # however we must ensure that this is not a "CC=gcc make" + ifeq "$(shell command -v $(CC) 2> /dev/null)" "" + # we do not have a valid CC variable so we try alternatives + ifeq "$(shell test -e '$(BIN_DIR)/clang' && echo 1)" "1" + # we found one in the local install directory, lets use these + CC = $(BIN_DIR)/clang + CXX = $(BIN_DIR)/clang++ + else + # hope for the best + $(warning we have trouble finding clang/clang++ - llvm-config is not helping us) + CC = clang + CXX = clang++ + endif endif endif # sanity check. # Are versions of clang --version and llvm-config --version equal? -CLANGVER = $(shell $(CC) --version | sed -E -ne '/^.*version\ ([0-9]\.[0-9]\.[0-9]).*/s//\1/p') +CLANGVER = $(shell $(CC) --version | sed -E -ne '/^.*version\ (1?[0-9]\.[0-9]\.[0-9]).*/s//\1/p') -ifneq "$(CLANGVER)" "$(LLVMVER)" - CC = $(shell $(LLVM_CONFIG) --bindir)/clang - CXX = $(shell $(LLVM_CONFIG) --bindir)/clang++ +# I disable this because it does not make sense with what we did before (marc) +# We did exactly set these 26 lines above with these values, and it would break +# "CC=gcc make" etc. usages +ifeq "$(findstring clang, $(shell $(CC) --version 2>/dev/null))" "" + CC_SAVE = $(LLVM_BINDIR)/clang +else + CC_SAVE = $(CC) +endif +ifeq "$(findstring clang, $(shell $(CXX) --version 2>/dev/null))" "" + CXX_SAVE = $(LLVM_BINDIR)/clang++ +else + CXX_SAVE = $(CXX) +endif + +CLANG_BIN = $(CC_SAVE) +CLANGPP_BIN = $(CXX_SAVE) + +ifeq "$(CC_SAVE)" "$(LLVM_BINDIR)/clang" + USE_BINDIR = 1 +else + ifeq "$(CXX_SAVE)" "$(LLVM_BINDIR)/clang++" + USE_BINDIR = 1 + else + USE_BINDIR = 0 + endif +endif + +# On old platform we cannot compile with clang because std++ libraries are too +# old. For these we need to use gcc/g++, so if we find REAL_CC and REAL_CXX +# variable we override the compiler variables here +ifneq "$(REAL_CC)" "" +CC = $(REAL_CC) +endif +ifneq "$(REAL_CXX)" "" +CXX = $(REAL_CXX) endif # After we set CC/CXX we can start makefile magic tests @@ -146,19 +182,6 @@ ifeq "$(shell echo 'int main() {return 0; }' | $(CC) -x c - -fuse-ld=`command -v endif endif -CLANG_BIN = $(basename $(CC)) -CLANGPP_BIN = $(basename $(CXX)) -ifeq "$(shell test -e $(CLANG_BIN) || echo 1 )" "1" - CLANG_BIN = $(CC) - CLANGPP_BIN = $(CXX) -endif - -ifeq "$(CC)" "$(LLVM_BINDIR)/clang" - USE_BINDIR = 1 -else - USE_BINDIR = 0 -endif - CFLAGS ?= -O3 -funroll-loops -D_FORTIFY_SOURCE=2 override CFLAGS += -Wall \ -g -Wno-pointer-sign -I ../include/ \ @@ -166,7 +189,7 @@ override CFLAGS += -Wall \ -DLLVM_BINDIR=\"$(LLVM_BINDIR)\" -DVERSION=\"$(VERSION)\" \ -DLLVM_VERSION=\"$(LLVMVER)\" -DAFL_CLANG_FLTO=\"$(AFL_CLANG_FLTO)\" \ -DAFL_REAL_LD=\"$(AFL_REAL_LD)\" -DAFL_CLANG_FUSELD=\"$(AFL_CLANG_FUSELD)\" \ - -DCLANG_BIN=\"$(CC)\" -DCLANGPP_BIN=\"$(CXX)\" -DUSE_BINDIR=$(USE_BINDIR) -Wno-unused-function + -DCLANG_BIN=\"$(CLANG_BIN)\" -DCLANGPP_BIN=\"$(CLANGPP_BIN)\" -DUSE_BINDIR=$(USE_BINDIR) -Wno-unused-function ifdef AFL_TRACE_PC $(info Compile option AFL_TRACE_PC is deprecated, just set AFL_LLVM_INSTRUMENT=PCGUARD to activate when compiling targets ) endif @@ -249,7 +272,7 @@ test_deps: @echo "[*] Checking for matching versions of '$(CC)' and '$(LLVM_CONFIG)'" ifneq "$(CLANGVER)" "$(LLVMVER)" @echo "[!] WARNING: we have llvm-config version $(LLVMVER) and a clang version $(CLANGVER)" - @echo "[!] Retrying with the clang compiler from llvm: CC=`llvm-config --bindir`/clang" + @echo "[!] Retry with the clang compiler from llvm: CC=`llvm-config --bindir`/clang" else @echo "[*] We have llvm-config version $(LLVMVER) with a clang version $(CLANGVER), good." endif @@ -290,9 +313,9 @@ endif ../afl-llvm-lto-instrumentation.so: afl-llvm-lto-instrumentation.so.cc afl-llvm-common.o ifeq "$(LLVM_LTO)" "1" $(CXX) $(CLANG_CFL) -Wno-writable-strings -fno-rtti -fPIC -std=$(LLVM_STDCXX) -shared $< -o $@ $(CLANG_LFL) afl-llvm-common.o - $(CC) $(CFLAGS) -Wno-unused-result -O0 $(AFL_CLANG_FLTO) -fPIC -c afl-llvm-rt-lto.o.c -o ../afl-llvm-rt-lto.o - @$(CC) $(CFLAGS) -Wno-unused-result -O0 $(AFL_CLANG_FLTO) -m64 -fPIC -c afl-llvm-rt-lto.o.c -o ../afl-llvm-rt-lto-64.o 2>/dev/null; if [ "$$?" = "0" ]; then : ; fi - @$(CC) $(CFLAGS) -Wno-unused-result -O0 $(AFL_CLANG_FLTO) -m32 -fPIC -c afl-llvm-rt-lto.o.c -o ../afl-llvm-rt-lto-32.o 2>/dev/null; if [ "$$?" = "0" ]; then : ; fi + $(CLANG_BIN) $(CFLAGS) -Wno-unused-result -O0 $(AFL_CLANG_FLTO) -fPIC -c afl-llvm-rt-lto.o.c -o ../afl-llvm-rt-lto.o + @$(CLANG_BIN) $(CFLAGS) -Wno-unused-result -O0 $(AFL_CLANG_FLTO) -m64 -fPIC -c afl-llvm-rt-lto.o.c -o ../afl-llvm-rt-lto-64.o 2>/dev/null; if [ "$$?" = "0" ]; then : ; fi + @$(CLANG_BIN) $(CFLAGS) -Wno-unused-result -O0 $(AFL_CLANG_FLTO) -m32 -fPIC -c afl-llvm-rt-lto.o.c -o ../afl-llvm-rt-lto-32.o 2>/dev/null; if [ "$$?" = "0" ]; then : ; fi endif # laf @@ -323,7 +346,7 @@ endif test_build: $(PROGS) @echo "[*] Testing the CC wrapper and instrumentation output..." - unset AFL_USE_ASAN AFL_USE_MSAN AFL_INST_RATIO; AFL_QUIET=1 AFL_PATH=. AFL_CC=$(CC) AFL_LLVM_LAF_SPLIT_SWITCHES=1 AFL_LLVM_LAF_TRANSFORM_COMPARES=1 AFL_LLVM_LAF_SPLIT_COMPARES=1 ../afl-clang-fast $(CFLAGS) ../test-instr.c -o test-instr $(LDFLAGS) + unset AFL_USE_ASAN AFL_USE_MSAN AFL_INST_RATIO; AFL_QUIET=1 AFL_PATH=. AFL_LLVM_LAF_SPLIT_SWITCHES=1 AFL_LLVM_LAF_TRANSFORM_COMPARES=1 AFL_LLVM_LAF_SPLIT_COMPARES=1 ../afl-clang-fast $(CFLAGS) ../test-instr.c -o test-instr $(LDFLAGS) ASAN_OPTIONS=detect_leaks=0 ../afl-showmap -m none -q -o .test-instr0 ./test-instr < /dev/null echo 1 | ASAN_OPTIONS=detect_leaks=0 ../afl-showmap -m none -q -o .test-instr1 ./test-instr @rm -f test-instr diff --git a/llvm_mode/README.md b/llvm_mode/README.md index 607350fb..0bff1ff1 100644 --- a/llvm_mode/README.md +++ b/llvm_mode/README.md @@ -37,7 +37,26 @@ co-exists with the original code. The idea and much of the implementation comes from Laszlo Szekeres. -## 2) How to use this +## 2a) How to use this - short + +Set the `LLVM_CONFIG` variable to the clang version you want to use, e.g. +``` +LLVM_CONFIG=llvm-config-9 make +``` +In case you have your own compiled llvm version specify the full path: +``` +LLVM_CONFIG=~/llvm-project/build/bin/llvm-config make +``` +If you try to use a new llvm version on an old Linux this can fail because of +old c++ libraries. In this case usually switching to gcc/g++ to compile +llvm_mode will work: +``` +LLVM_CONFIG=llvm-config-7 REAL_CC=gcc REAL_CXX=g++ make +``` +It is highly recommended to use the newest clang version you can put your +hands on :) + +## 2b) How to use this - long In order to leverage this mechanism, you need to have clang installed on your system. You should also make sure that the llvm-config tool is in your path diff --git a/llvm_mode/afl-llvm-rt.o.c b/llvm_mode/afl-llvm-rt.o.c index 8867ae36..722ca421 100644 --- a/llvm_mode/afl-llvm-rt.o.c +++ b/llvm_mode/afl-llvm-rt.o.c @@ -152,7 +152,7 @@ static void __afl_map_shm(void) { if (getenv("AFL_DEBUG")) fprintf(stderr, - "DEBUG: id_str %s, __afl_map_addr 0x%x, MAP_SIZE %u, " + "DEBUG: id_str %s, __afl_map_addr 0x%lx, MAP_SIZE %u, " "__afl_final_loc %u, max_size_forkserver %u/0x%x\n", id_str == NULL ? "<null>" : id_str, __afl_map_addr, MAP_SIZE, __afl_final_loc, FS_OPT_MAX_MAPSIZE, FS_OPT_MAX_MAPSIZE); diff --git a/qemu_mode/patches/afl-qemu-cpu-inl.h b/qemu_mode/patches/afl-qemu-cpu-inl.h index 06243141..6e9ddc3b 100644 --- a/qemu_mode/patches/afl-qemu-cpu-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-inl.h @@ -275,20 +275,6 @@ void afl_setup(void) { } -static void print_mappings(void) { - - u8 buf[MAX_LINE]; - FILE *f = fopen("/proc/self/maps", "r"); - - if (!f) return; - - while (fgets(buf, MAX_LINE, f)) - printf("%s", buf); - - fclose(f); - -} - /* Fork server logic, invoked once we hit _start. */ void afl_forkserver(CPUState *cpu) { @@ -299,7 +285,7 @@ void afl_forkserver(CPUState *cpu) { if (forkserver_installed == 1) return; forkserver_installed = 1; - if (getenv("AFL_QEMU_DEBUG_MAPS")) print_mappings(); + if (getenv("AFL_QEMU_DEBUG_MAPS")) open_self_maps(cpu->env_ptr, 0); // if (!afl_area_ptr) return; // not necessary because of fixed dummy buffer diff --git a/qemu_mode/patches/syscall.diff b/qemu_mode/patches/syscall.diff index 775fc9e0..b8c5ff39 100644 --- a/qemu_mode/patches/syscall.diff +++ b/qemu_mode/patches/syscall.diff @@ -1,5 +1,5 @@ diff --git a/linux-user/syscall.c b/linux-user/syscall.c -index b13a170e..4af79175 100644 +index b13a170e..3f5cc902 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -111,6 +111,9 @@ @@ -43,6 +43,15 @@ index b13a170e..4af79175 100644 ts = (TaskState *)cpu->opaque; if (flags & CLONE_SETTLS) cpu_set_tls (env, newtls); +@@ -6554,7 +6558,7 @@ static int open_self_cmdline(void *cpu_env, int fd) + return 0; + } + +-static int open_self_maps(void *cpu_env, int fd) ++int open_self_maps(void *cpu_env, int fd) + { + CPUState *cpu = ENV_GET_CPU((CPUArchState *)cpu_env); + TaskState *ts = cpu->opaque; @@ -7324,10 +7328,12 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, #ifdef TARGET_NR_stime /* not on alpha */ case TARGET_NR_stime: diff --git a/src/afl-common.c b/src/afl-common.c index dda62219..8f21ad94 100644 --- a/src/afl-common.c +++ b/src/afl-common.c @@ -71,7 +71,7 @@ char *afl_environment_variables[] = { "AFL_NGRAM_SIZE", "AFL_LLVM_NOT_ZERO", "AFL_LLVM_WHITELIST", "AFL_NO_AFFINITY", "AFL_LLVM_LTO_STARTID", "AFL_LLVM_LTO_DONTWRITEID", "AFL_NO_ARITH", "AFL_NO_BUILTIN", "AFL_NO_CPU_RED", "AFL_NO_FORKSRV", - "AFL_NO_UI", "AFL_NO_PYTHON", + "AFL_NO_UI", "AFL_NO_PYTHON", "AFL_UNTRACER_FILE", "AFL_NO_X86", // not really an env but we dont want to warn on it "AFL_MAP_SIZE", "AFL_MAPSIZE", "AFL_PATH", "AFL_PERFORMANCE_FILE", //"AFL_PERSISTENT", // not implemented anymore, so warn additionally diff --git a/src/afl-forkserver.c b/src/afl-forkserver.c index d5a60077..c1623f22 100644 --- a/src/afl-forkserver.c +++ b/src/afl-forkserver.c @@ -790,8 +790,6 @@ fsrv_run_result_t afl_fsrv_run_target(afl_forkserver_t *fsrv, u32 timeout, s32 res; u32 exec_ms; - int status = 0; - /* After this memset, fsrv->trace_bits[] are effectively volatile, so we must prevent any earlier operations from venturing into that territory. */ @@ -821,7 +819,8 @@ fsrv_run_result_t afl_fsrv_run_target(afl_forkserver_t *fsrv, u32 timeout, if (fsrv->child_pid <= 0) { FATAL("Fork server is misbehaving (OOM?)"); } - exec_ms = read_timed(fsrv->fsrv_st_fd, &status, 4, timeout, stop_soon_p); + exec_ms = read_timed(fsrv->fsrv_st_fd, &fsrv->child_status, 4, timeout, + stop_soon_p); if (exec_ms > timeout) { @@ -830,7 +829,7 @@ fsrv_run_result_t afl_fsrv_run_target(afl_forkserver_t *fsrv, u32 timeout, kill(fsrv->child_pid, SIGKILL); fsrv->last_run_timed_out = 1; - if (read(fsrv->fsrv_st_fd, &status, 4) < 4) { exec_ms = 0; } + if (read(fsrv->fsrv_st_fd, &fsrv->child_status, 4) < 4) { exec_ms = 0; } } @@ -862,7 +861,7 @@ fsrv_run_result_t afl_fsrv_run_target(afl_forkserver_t *fsrv, u32 timeout, } - if (!WIFSTOPPED(status)) { fsrv->child_pid = 0; } + if (!WIFSTOPPED(fsrv->child_status)) { fsrv->child_pid = 0; } fsrv->total_execs++; @@ -874,9 +873,9 @@ fsrv_run_result_t afl_fsrv_run_target(afl_forkserver_t *fsrv, u32 timeout, /* Report outcome to caller. */ - if (WIFSIGNALED(status) && !*stop_soon_p) { + if (WIFSIGNALED(fsrv->child_status) && !*stop_soon_p) { - fsrv->last_kill_signal = WTERMSIG(status); + fsrv->last_kill_signal = WTERMSIG(fsrv->child_status); if (fsrv->last_run_timed_out && fsrv->last_kill_signal == SIGKILL) { @@ -891,7 +890,7 @@ fsrv_run_result_t afl_fsrv_run_target(afl_forkserver_t *fsrv, u32 timeout, /* A somewhat nasty hack for MSAN, which doesn't support abort_on_error and must use a special exit code. */ - if (fsrv->uses_asan && WEXITSTATUS(status) == MSAN_ERROR) { + if (fsrv->uses_asan && WEXITSTATUS(fsrv->child_status) == MSAN_ERROR) { fsrv->last_kill_signal = 0; return FSRV_RUN_CRASH; diff --git a/test/test.sh b/test/test.sh index b8d4208f..e950e3de 100755 --- a/test/test.sh +++ b/test/test.sh @@ -802,7 +802,6 @@ test -e ../afl-qemu-trace && { echo CUT------------------------------------------------------------------CUT $ECHO "$RED[!] afl-fuzz is not working correctly with persistent qemu_mode" CODE=1 - exit 1 } rm -rf in out errors } || { diff --git a/unicorn_mode/UNICORNAFL_VERSION b/unicorn_mode/UNICORNAFL_VERSION index 0afcf291..3d95ba0b 100644 --- a/unicorn_mode/UNICORNAFL_VERSION +++ b/unicorn_mode/UNICORNAFL_VERSION @@ -1 +1 @@ -25ae270 +f8e3792ed07710c5138e016376b73298999a35dc diff --git a/unicorn_mode/samples/persistent/Makefile b/unicorn_mode/samples/persistent/Makefile index cb491e10..9c7ed7aa 100644 --- a/unicorn_mode/samples/persistent/Makefile +++ b/unicorn_mode/samples/persistent/Makefile @@ -45,3 +45,6 @@ harness: harness.o debug: harness-debug.o ${MYCC} -L${LIBDIR} harness.o ../../unicornafl/libunicornafl.a $(LDFLAGS) -o harness-debug + +fuzz: harness + ../../../afl-fuzz -m none -i sample_inputs -o out -- ./harness @@ diff --git a/unicorn_mode/samples/persistent/harness.c b/unicorn_mode/samples/persistent/harness.c index 02d96e90..3d379f46 100644 --- a/unicorn_mode/samples/persistent/harness.c +++ b/unicorn_mode/samples/persistent/harness.c @@ -151,7 +151,7 @@ static void mem_map_checked(uc_engine *uc, uint64_t addr, size_t size, uint32_t //printf("SIZE %llx, align: %llx\n", size, ALIGNMENT); uc_err err = uc_mem_map(uc, addr, size, mode); if (err != UC_ERR_OK) { - printf("Error mapping %ld bytes at 0x%lx: %s (mode: %d)\n", size, addr, uc_strerror(err), mode); + printf("Error mapping %zu bytes at 0x%llx: %s (mode: %d)\n", size, (unsigned long long) addr, uc_strerror(err), mode); exit(1); } } @@ -213,7 +213,7 @@ int main(int argc, char **argv, char **envp) { // Setup the Stack mem_map_checked(uc, STACK_ADDRESS - STACK_SIZE, STACK_SIZE, UC_PROT_READ | UC_PROT_WRITE); uint64_t stack_val = STACK_ADDRESS; - printf("%lu", stack_val); + printf("%llu", (unsigned long long) stack_val); uc_reg_write(uc, UC_X86_REG_RSP, &stack_val); // reserve some space for our input data diff --git a/unicorn_mode/samples/persistent/persistent_target b/unicorn_mode/samples/persistent/persistent_target new file mode 100755 index 00000000..83421a4f --- /dev/null +++ b/unicorn_mode/samples/persistent/persistent_target Binary files differdiff --git a/unicorn_mode/unicornafl b/unicorn_mode/unicornafl -Subproject 25ae270c1b949a5d1c2c5460b778f0a35bfe67d +Subproject f8e3792ed07710c5138e016376b73298999a35d |