From 01ad7610beaf772063c9011daae5fa3a3232494c Mon Sep 17 00:00:00 2001 From: realmadsci <71108352+realmadsci@users.noreply.github.com> Date: Mon, 15 Mar 2021 11:45:58 -0400 Subject: Remove AFL_PRELOAD and AFL_USE_QASAN handlers These are now processed in afl-qemu-trace so that the "copy+paste" code that is in all of the other AFL tools can be removed. This also allows the AFL_USE_QASAN flag to work the same when used with tools like afl-fuzz as it does with afl-qemu-trace. This is important in situations where loading the QASAN library changes the address of your desired entrypoint, or for crash validation using the same environment that afl-fuzz was using. With this change, the same set of environment variables can be used in exactly the same way between afl-fuzz, afl-showmap, and afl-qemu-trace, and you will get exactly the same guest environment. --- include/common.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/common.h') diff --git a/include/common.h b/include/common.h index cd728536..b7adbaec 100644 --- a/include/common.h +++ b/include/common.h @@ -48,7 +48,6 @@ void argv_cpy_free(char **argv); char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv); char **get_wine_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv); char * get_afl_env(char *env); -u8 * get_libqasan_path(u8 *own_loc); extern u8 be_quiet; extern u8 *doc_path; /* path to documentation dir */ -- cgit 1.4.1 From e73c7c59c14d0bff1c1b25aa264fe18b7cdcddaf Mon Sep 17 00:00:00 2001 From: vanhauser-thc Date: Fri, 19 Mar 2021 14:55:25 +0100 Subject: refactor finding binaries --- .github/workflows/ci.yml | 4 +- .github/workflows/codeql-analysis.yml | 4 +- include/common.h | 4 + include/envs.h | 1 + src/afl-common.c | 228 +++++++++++----------------------- 5 files changed, 79 insertions(+), 162 deletions(-) (limited to 'include/common.h') diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml index 8412fcbb..31cfceaf 100644 --- a/.github/workflows/ci.yml +++ b/.github/workflows/ci.yml @@ -3,8 +3,8 @@ name: CI on: push: branches: [ stable, dev ] -# pull_request: -# branches: [ stable, dev ] + pull_request: + branches: [ stable, dev ] jobs: build: diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml index e6c166f2..eda8dfd0 100644 --- a/.github/workflows/codeql-analysis.yml +++ b/.github/workflows/codeql-analysis.yml @@ -3,8 +3,8 @@ name: "CodeQL" on: push: branches: [ stable, dev ] -# pull_request: -# branches: [ stable, dev ] + pull_request: + branches: [ stable, dev ] jobs: analyze: diff --git a/include/common.h b/include/common.h index b7adbaec..46585c88 100644 --- a/include/common.h +++ b/include/common.h @@ -57,6 +57,10 @@ extern u8 *doc_path; /* path to documentation dir */ u8 *find_binary(u8 *fname); +/* find an afl binary */ + +u8 *find_afl_binary(u8 *own_loc, u8 *fname); + /* Parses the kill signal environment variable, FATALs on error. If the env is not set, sets the env to default_signal for the signal handlers and returns the default_signal. */ diff --git a/include/envs.h b/include/envs.h index cfd73b68..2ce50be7 100644 --- a/include/envs.h +++ b/include/envs.h @@ -42,6 +42,7 @@ static char *afl_environment_variables[] = { "AFL_DEBUG_CHILD", "AFL_DEBUG_GDB", "AFL_DISABLE_TRIM", + "AFL_DISABLE_LLVM_INSTRUMENTATION", "AFL_DONT_OPTIMIZE", "AFL_DRIVER_STDERR_DUPLICATE_FILENAME", "AFL_DUMB_FORKSRV", diff --git a/src/afl-common.c b/src/afl-common.c index 7e56ce3f..04736901 100644 --- a/src/afl-common.c +++ b/src/afl-common.c @@ -158,10 +158,6 @@ char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { } - if (!unlikely(own_loc)) { FATAL("BUG: param own_loc is NULL"); } - - u8 *tmp, *cp = NULL, *rsl, *own_copy; - char **new_argv = ck_alloc(sizeof(char *) * (argc + 4)); if (unlikely(!new_argv)) { FATAL("Illegal amount of arguments specified"); } @@ -173,70 +169,8 @@ char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { /* Now we need to actually find the QEMU binary to put in argv[0]. */ - tmp = getenv("AFL_PATH"); - - if (tmp) { - - cp = alloc_printf("%s/afl-qemu-trace", tmp); - - if (access(cp, X_OK)) { FATAL("Unable to find '%s'", tmp); } - - *target_path_p = new_argv[0] = cp; - return new_argv; - - } - - own_copy = ck_strdup(own_loc); - rsl = strrchr(own_copy, '/'); - - if (rsl) { - - *rsl = 0; - - cp = alloc_printf("%s/afl-qemu-trace", own_copy); - ck_free(own_copy); - - if (!access(cp, X_OK)) { - - *target_path_p = new_argv[0] = cp; - return new_argv; - - } - - } else { - - ck_free(own_copy); - - } - - if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { - - if (cp) { ck_free(cp); } - *target_path_p = new_argv[0] = ck_strdup(BIN_PATH "/afl-qemu-trace"); - - return new_argv; - - } - - SAYF("\n" cLRD "[-] " cRST - "Oops, unable to find the 'afl-qemu-trace' binary. The binary must be " - "built\n" - " separately by following the instructions in " - "qemu_mode/README.md. " - "If you\n" - " already have the binary installed, you may need to specify " - "AFL_PATH in the\n" - " environment.\n\n" - - " Of course, even without QEMU, afl-fuzz can still work with " - "binaries that are\n" - " instrumented at compile time with afl-gcc. It is also possible to " - "use it as a\n" - " traditional non-instrumented fuzzer by specifying '-n' in the " - "command " - "line.\n"); - - FATAL("Failed to locate 'afl-qemu-trace'."); + *target_path_p = new_argv[0] = find_afl_binary(own_loc, "afl-qemu-trace"); + return new_argv; } @@ -244,10 +178,6 @@ char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { char **get_wine_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { - if (!unlikely(own_loc)) { FATAL("BUG: param own_loc is NULL"); } - - u8 *tmp, *cp = NULL, *rsl, *own_copy; - char **new_argv = ck_alloc(sizeof(char *) * (argc + 3)); if (unlikely(!new_argv)) { FATAL("Illegal amount of arguments specified"); } @@ -258,92 +188,10 @@ char **get_wine_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { /* Now we need to actually find the QEMU binary to put in argv[0]. */ - tmp = getenv("AFL_PATH"); - - if (tmp) { - - cp = alloc_printf("%s/afl-qemu-trace", tmp); - - if (access(cp, X_OK)) { FATAL("Unable to find '%s'", tmp); } - - ck_free(cp); - - cp = alloc_printf("%s/afl-wine-trace", tmp); - - if (access(cp, X_OK)) { FATAL("Unable to find '%s'", tmp); } - - *target_path_p = new_argv[0] = cp; - return new_argv; - - } - - own_copy = ck_strdup(own_loc); - rsl = strrchr(own_copy, '/'); - - if (rsl) { - - *rsl = 0; - - cp = alloc_printf("%s/afl-qemu-trace", own_copy); - - if (cp && !access(cp, X_OK)) { - - ck_free(cp); - - cp = alloc_printf("%s/afl-wine-trace", own_copy); - - if (!access(cp, X_OK)) { - - *target_path_p = new_argv[0] = cp; - return new_argv; - - } - - } - - ck_free(own_copy); - - } else { - - ck_free(own_copy); - - } - - u8 *ncp = BIN_PATH "/afl-qemu-trace"; - - if (!access(ncp, X_OK)) { - - ncp = BIN_PATH "/afl-wine-trace"; - - if (!access(ncp, X_OK)) { - - *target_path_p = new_argv[0] = ck_strdup(ncp); - return new_argv; - - } - - } - - SAYF("\n" cLRD "[-] " cRST - "Oops, unable to find the '%s' binary. The binary must be " - "built\n" - " separately by following the instructions in " - "qemu_mode/README.md. " - "If you\n" - " already have the binary installed, you may need to specify " - "AFL_PATH in the\n" - " environment.\n\n" - - " Of course, even without QEMU, afl-fuzz can still work with " - "binaries that are\n" - " instrumented at compile time with afl-gcc. It is also possible to " - "use it as a\n" - " traditional non-instrumented fuzzer by specifying '-n' in the " - "command " - "line.\n", - ncp); - - FATAL("Failed to locate '%s'.", ncp); + u8 *tmp = find_afl_binary(own_loc, "afl-qemu-trace"); + ck_free(tmp); + *target_path_p = new_argv[0] = find_afl_binary(own_loc, "afl-wine-trace"); + return new_argv; } @@ -437,6 +285,70 @@ u8 *find_binary(u8 *fname) { } +u8 *find_afl_binary(u8 *own_loc, u8 *fname) { + + u8 *afl_path = NULL, *target_path, *own_copy; + + if ((afl_path = getenv("AFL_PATH"))) { + + target_path = alloc_printf("%s/%s", afl_path, fname); + if (!access(target_path, X_OK)) { + + return target_path; + + } else { + + ck_free(target_path); + + } + + } + + if (own_loc) { + + own_copy = ck_strdup(own_loc); + u8 *rsl = strrchr(own_copy, '/'); + + if (rsl) { + + *rsl = 0; + + target_path = alloc_printf("%s/%s", own_copy, fname); + ck_free(own_copy); + + if (!access(target_path, X_OK)) { + + return target_path; + + } else { + + ck_free(target_path); + + } + + } else { + + ck_free(own_copy); + + } + + } + + target_path = alloc_printf("%s/%s", BIN_PATH, fname); + if (!access(target_path, X_OK)) { + + return target_path; + + } else { + + ck_free(target_path); + + } + + return find_binary(fname); + +} + /* Parses the kill signal environment variable, FATALs on error. If the env is not set, sets the env to default_signal for the signal handlers and returns the default_signal. */ -- cgit 1.4.1 From d7e121e2c99c02d4b6984f21ba837d44bce9c77c Mon Sep 17 00:00:00 2001 From: fuzzah Date: Wed, 17 Mar 2021 01:51:40 +0300 Subject: add AFL_TARGET_ENV to afl-fuzz --- README.md | 1 + docs/Changelog.md | 3 ++ docs/env_variables.md | 6 ++++ include/common.h | 4 +++ include/envs.h | 1 + src/afl-common.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/afl-fuzz.c | 8 +++++ 7 files changed, 119 insertions(+) (limited to 'include/common.h') diff --git a/README.md b/README.md index 69e5bb74..700fe818 100644 --- a/README.md +++ b/README.md @@ -1178,6 +1178,7 @@ without feedback, bug reports, or patches from: Josephine Calliotte Konrad Welc Thomas Rooijakkers David Carlier Ruben ten Hove Joey Jiao + fuzzah ``` Thank you! diff --git a/docs/Changelog.md b/docs/Changelog.md index bf04c58e..fdb1cf5c 100644 --- a/docs/Changelog.md +++ b/docs/Changelog.md @@ -9,6 +9,9 @@ Want to stay in the loop on major new features? Join our mailing list by sending a mail to . ### Version ++3.12a (dev) + - afl-fuzz: + - added AFL_TARGET_ENV variable to pass extra env vars to the target + (for things like LD_LIBRARY_PATH) - afl-cc: - fix cmplog rtn (rare crash and not being able to gather ptr data) - link runtime not to shared libs diff --git a/docs/env_variables.md b/docs/env_variables.md index c6ad0aa4..96fd520f 100644 --- a/docs/env_variables.md +++ b/docs/env_variables.md @@ -408,6 +408,12 @@ checks or alter some of the more exotic semantics of the tool: without disrupting the afl-fuzz process itself. This is useful, among other things, for bootstrapping libdislocator.so. + - Setting `AFL_TARGET_ENV` causes AFL++ to set extra environment variables + for the target binary. Example: `AFL_TARGET_ENV="VAR1=1 VAR2='a b c'" afl-fuzz ... ` + This exists mostly for things like `LD_LIBRARY_PATH` but it would theoretically + allow fuzzing of AFL++ itself (with 'target' AFL++ using some AFL_ vars that + would disrupt work of 'fuzzer' AFL++). + - Setting `AFL_NO_UI` inhibits the UI altogether, and just periodically prints some basic stats. This behavior is also automatically triggered when the output from afl-fuzz is redirected to a file or to a pipe. diff --git a/include/common.h b/include/common.h index b7adbaec..06453b8e 100644 --- a/include/common.h +++ b/include/common.h @@ -49,6 +49,10 @@ char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv); char **get_wine_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv); char * get_afl_env(char *env); +/* Extract env vars from input string and set them using setenv() + For use with AFL_TARGET_ENV, ... */ +u8 extract_and_set_env(u8 *env_str); + extern u8 be_quiet; extern u8 *doc_path; /* path to documentation dir */ diff --git a/include/envs.h b/include/envs.h index cfd73b68..fda4ab55 100644 --- a/include/envs.h +++ b/include/envs.h @@ -130,6 +130,7 @@ static char *afl_environment_variables[] = { "AFL_PATH", "AFL_PERFORMANCE_FILE", "AFL_PRELOAD", + "AFL_TARGET_ENV", "AFL_PYTHON_MODULE", "AFL_QEMU_CUSTOM_BIN", "AFL_QEMU_COMPCOV", diff --git a/src/afl-common.c b/src/afl-common.c index 27b63434..72a95fbc 100644 --- a/src/afl-common.c +++ b/src/afl-common.c @@ -706,6 +706,102 @@ char *get_afl_env(char *env) { } +u8 extract_and_set_env(u8 *env_str) { + + if (!env_str) { return 0; } + + u8 *p = ck_strdup(env_str); + + u8 *end = p + strlen((char *)p); + + u8 ret_val = 0; // return false by default + + u8 *rest = p; + u8 *key = p; + u8 *val = p; + + u8 closing_sym = ' '; + u8 c; + + size_t num_pairs = 0; + + while (rest < end) { + + while (*rest == ' ') { + + rest++; + + } + + if (rest + 1 >= end) break; + + key = rest; + // env variable names may not start with numbers or '=' + if (*key == '=' || (*key >= '0' && *key <= '9')) { goto free_and_return; } + + while (rest < end && *rest != '=' && *rest != ' ') { + + c = *rest; + // lowercase is bad but we may still allow it + if ((c < 'A' || c > 'Z') && (c < 'a' || c > 'z') && + (c < '0' || c > '9') && c != '_') { + + goto free_and_return; + + } + + rest++; + + } + + if (*rest != '=') { goto free_and_return; } + + *rest = '\0'; // done with variable name + + rest += 1; + if (rest >= end || *rest == ' ') { goto free_and_return; } + + val = rest; + if (*val == '\'' || *val == '"') { + + closing_sym = *val; + val += 1; + rest += 1; + if (rest >= end) { goto free_and_return; } + + } else { + + closing_sym = ' '; + + } + + while (rest < end && *rest != closing_sym) { + + rest++; + + } + + if (closing_sym != ' ' && *rest != closing_sym) { goto free_and_return; } + + *rest = '\0'; // done with variable value + + rest += 1; + if (rest < end && *rest != ' ') { goto free_and_return; } + + num_pairs += 1; + + setenv(key, val, 1); + + } + + if (num_pairs > 0) { ret_val = 1; } + +free_and_return: + ck_free(p); + return ret_val; + +} + /* Read mask bitmap from file. This is for the -B option. */ void read_bitmap(u8 *fname, u8 *map, size_t len) { diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c index cfb507a7..9ea1fb34 100644 --- a/src/afl-fuzz.c +++ b/src/afl-fuzz.c @@ -223,6 +223,7 @@ static void usage(u8 *argv0, int more_help) { "AFL_PYTHON_MODULE: mutate and trim inputs with the specified Python module\n" "AFL_QUIET: suppress forkserver status messages\n" "AFL_PRELOAD: LD_PRELOAD / DYLD_INSERT_LIBRARIES settings for target\n" + "AFL_TARGET_ENV: pass extra environment variables to target\n" "AFL_SHUFFLE_QUEUE: reorder the input queue randomly on startup\n" "AFL_SKIP_BIN_CHECK: skip the check, if the target is an executable\n" "AFL_SKIP_CPUFREQ: do not warn about variable cpu clocking\n" @@ -1303,6 +1304,13 @@ int main(int argc, char **argv_orig, char **envp) { } + u8 *extra_env = (u8 *)getenv("AFL_TARGET_ENV"); + if (extra_env && !extract_and_set_env(extra_env)) { + + FATAL("Bad value of AFL_TARGET_ENV"); + + } + save_cmdline(afl, argc, argv); fix_up_banner(afl, argv[optind]); -- cgit 1.4.1 From 5fcd634f05049564dde59df420ac1c2f291a2fb0 Mon Sep 17 00:00:00 2001 From: Dominik Maier Date: Tue, 23 Mar 2021 18:47:07 +0100 Subject: fixed tiny nitpicks --- docs/env_variables.md | 2 +- include/afl-fuzz.h | 2 +- include/common.h | 2 +- src/afl-common.c | 22 +++++++++------------- src/afl-fuzz-state.c | 7 +++++++ src/afl-fuzz.c | 4 ++-- 6 files changed, 21 insertions(+), 18 deletions(-) (limited to 'include/common.h') diff --git a/docs/env_variables.md b/docs/env_variables.md index 7eb973e5..409425f1 100644 --- a/docs/env_variables.md +++ b/docs/env_variables.md @@ -426,7 +426,7 @@ checks or alter some of the more exotic semantics of the tool: - If you are Jakub, you may need `AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES`. Others need not apply, unless they also want to disable the - /proc/sys/kernel/core_pattern check. + `/proc/sys/kernel/core_pattern` check. - Benchmarking only: `AFL_BENCH_JUST_ONE` causes the fuzzer to exit after processing the first queue entry; and `AFL_BENCH_UNTIL_CRASH` causes it to diff --git a/include/afl-fuzz.h b/include/afl-fuzz.h index 5003b563..565e9afd 100644 --- a/include/afl-fuzz.h +++ b/include/afl-fuzz.h @@ -390,7 +390,7 @@ typedef struct afl_env_vars { *afl_hang_tmout, *afl_forksrv_init_tmout, *afl_skip_crashes, *afl_preload, *afl_max_det_extras, *afl_statsd_host, *afl_statsd_port, *afl_crash_exitcode, *afl_statsd_tags_flavor, *afl_testcache_size, - *afl_testcache_entries, *afl_kill_signal; + *afl_testcache_entries, *afl_kill_signal, *afl_target_env; } afl_env_vars_t; diff --git a/include/common.h b/include/common.h index 05137fb6..7bba9e91 100644 --- a/include/common.h +++ b/include/common.h @@ -51,7 +51,7 @@ char * get_afl_env(char *env); /* Extract env vars from input string and set them using setenv() For use with AFL_TARGET_ENV, ... */ -u8 extract_and_set_env(u8 *env_str); +bool extract_and_set_env(u8 *env_str); extern u8 be_quiet; extern u8 *doc_path; /* path to documentation dir */ diff --git a/src/afl-common.c b/src/afl-common.c index 6e485117..cd24c376 100644 --- a/src/afl-common.c +++ b/src/afl-common.c @@ -618,19 +618,15 @@ char *get_afl_env(char *env) { } -u8 extract_and_set_env(u8 *env_str) { +bool extract_and_set_env(u8 *env_str) { - if (!env_str) { return 0; } + if (!env_str) { return false; } - u8 *p = ck_strdup(env_str); + bool ret = false; // return false by default + u8 *p = ck_strdup(env_str); u8 *end = p + strlen((char *)p); - - u8 ret_val = 0; // return false by default - u8 *rest = p; - u8 *key = p; - u8 *val = p; u8 closing_sym = ' '; u8 c; @@ -647,7 +643,7 @@ u8 extract_and_set_env(u8 *env_str) { if (rest + 1 >= end) break; - key = rest; + u8 *key = rest; // env variable names may not start with numbers or '=' if (*key == '=' || (*key >= '0' && *key <= '9')) { goto free_and_return; } @@ -673,7 +669,7 @@ u8 extract_and_set_env(u8 *env_str) { rest += 1; if (rest >= end || *rest == ' ') { goto free_and_return; } - val = rest; + u8 *val = rest; if (*val == '\'' || *val == '"') { closing_sym = *val; @@ -700,17 +696,17 @@ u8 extract_and_set_env(u8 *env_str) { rest += 1; if (rest < end && *rest != ' ') { goto free_and_return; } - num_pairs += 1; + num_pairs++; setenv(key, val, 1); } - if (num_pairs > 0) { ret_val = 1; } + if (num_pairs) { ret = true; } free_and_return: ck_free(p); - return ret_val; + return ret; } diff --git a/src/afl-fuzz-state.c b/src/afl-fuzz-state.c index 3d36e712..0ddf8cf3 100644 --- a/src/afl-fuzz-state.c +++ b/src/afl-fuzz-state.c @@ -433,6 +433,13 @@ void read_afl_environment(afl_state_t *afl, char **envp) { afl->afl_env.afl_kill_signal = (u8 *)get_afl_env(afl_environment_variables[i]); + } else if (!strncmp(env, "AFL_TARGET_ENV", + + afl_environment_variable_len)) { + + afl->afl_env.afl_target_env = + (u8 *)get_afl_env(afl_environment_variables[i]); + } } else { diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c index b1d01959..d70ffd31 100644 --- a/src/afl-fuzz.c +++ b/src/afl-fuzz.c @@ -1304,8 +1304,8 @@ int main(int argc, char **argv_orig, char **envp) { } - u8 *extra_env = (u8 *)getenv("AFL_TARGET_ENV"); - if (extra_env && !extract_and_set_env(extra_env)) { + if (afl->afl_env.afl_target_env && + !extract_and_set_env(afl->afl_env.afl_target_env)) { FATAL("Bad value of AFL_TARGET_ENV"); -- cgit 1.4.1