/* american fuzzy lop++ - redqueen implementation on top of cmplog --------------------------------------------------------------- Originally written by Michal Zalewski Forkserver design by Jann Horn Now maintained by by Marc Heuse , Heiko Eißfeldt and Andrea Fioraldi 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 Shared code to handle the shared memory. This is used by the fuzzer as well the other components like afl-tmin, afl-showmap, etc... */ #include "afl-fuzz.h" #include "cmplog.h" static char** its_argv; ///// Colorization struct range { u32 start; u32 end; struct range* next; }; struct range* add_range(struct range* ranges, u32 start, u32 end) { struct range* r = ck_alloc_nozero(sizeof(struct range)); r->start = start; r->end = end; r->next = ranges; return r; } struct range* pop_biggest_range(struct range** ranges) { struct range* r = *ranges; struct range* prev = NULL; struct range* rmax = NULL; struct range* prev_rmax = NULL; u32 max_size = 0; while (r) { u32 s = r->end - r->start; if (s >= max_size) { max_size = s; prev_rmax = prev; rmax = r; } prev = r; r = r->next; } if (rmax) { if (prev_rmax) prev_rmax->next = rmax->next; else *ranges = rmax->next; } return rmax; } u8 get_exec_checksum(u8* buf, u32 len, u32* cksum) { if (unlikely(common_fuzz_stuff(its_argv, buf, len))) return 1; *cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); return 0; } static void rand_replace(u8* buf, u32 len) { u32 i; for (i = 0; i < len; ++i) buf[i] = UR(256); } u8 colorization(u8* buf, u32 len, u32 exec_cksum) { struct range* ranges = add_range(NULL, 0, len); u8* backup = ck_alloc_nozero(len); u8 needs_write = 0; u64 orig_hit_cnt, new_hit_cnt; orig_hit_cnt = queued_paths + unique_crashes; stage_name = "colorization"; stage_short = "colorization"; stage_max = 1000; struct range* rng; stage_cur = 0; while ((rng = pop_biggest_range(&ranges)) != NULL && stage_cur < stage_max) { u32 s = rng->end - rng->start; if (s == 0) goto empty_range; memcpy(backup, buf + rng->start, s); rand_replace(buf + rng->start, s); u32 cksum; if (unlikely(get_exec_checksum(buf, len, &cksum))) goto checksum_fail; if (cksum != exec_cksum) { ranges = add_range(ranges, rng->start, rng->start + s / 2); ranges = add_range(ranges, rng->start + s / 2 + 1, rng->end); memcpy(buf + rng->start, backup, s); } else needs_write = 1; empty_range: ck_free(rng); ++stage_cur; } if (stage_cur < stage_max) queue_cur->fully_colorized = 1; new_hit_cnt = queued_paths + unique_crashes; stage_finds[STAGE_COLORIZATION] += new_hit_cnt - orig_hit_cnt; stage_cycles[STAGE_COLORIZATION] += stage_cur; ck_free(backup); while (ranges) { rng = ranges; ranges = ranges->next; ck_free(rng); } // save the input with the high entropy if (needs_write) { s32 fd; if (no_unlink) { fd = open(queue_cur->fname, O_WRONLY | O_CREAT | O_TRUNC, 0600); } else { unlink(queue_cur->fname); /* ignore errors */ fd = open(queue_cur->fname, O_WRONLY | O_CREAT | O_EXCL, 0600); } if (fd < 0) PFATAL("Unable to create '%s'", queue_cur->fname); ck_write(fd, buf, len, queue_cur->fname); queue_cur->len = len; // no-op, just to be 100% safe close(fd); } return 0; checksum_fail: ck_free(backup); while (ranges) { rng = ranges; ranges = ranges->next; ck_free(rng); } return 1; } ///// Input to State replacement u8 its_fuzz(u8* buf, u32 len, u8* status) { u64 orig_hit_cnt, new_hit_cnt; orig_hit_cnt = queued_paths + unique_crashes; if (unlikely(common_fuzz_stuff(its_argv, buf, len))) return 1; new_hit_cnt = queued_paths + unique_crashes; if (unlikely(new_hit_cnt != orig_hit_cnt)) *status = 1; else *status = 2; return 0; } u8 cmp_extend_encoding(struct cmp_header* h, u64 pattern, u64 repl, u32 idx, u8* orig_buf, u8* buf, u32 len, u8 do_reverse, u8* status) { u64* buf_64 = (u64*)&buf[idx]; u32* buf_32 = (u32*)&buf[idx]; u16* buf_16 = (u16*)&buf[idx]; // u8* buf_8 = &buf[idx]; // u64* o_buf_64 = (u64*)&orig_buf[idx]; // u32* o_buf_32 = (u32*)&orig_buf[idx]; // u16* o_buf_16 = (u16*)&orig_buf[idx]; // u8* o_buf_8 = &orig_buf[idx]; u32 its_len = len - idx; *status = 0; if (SHAPE_BYTES(h->shape) == 8) { if (its_len >= 8 && *buf_64 == pattern) { // && *o_buf_64 == pattern) { *buf_64 = repl; if (unlikely(its_fuzz(buf, len, status))) return 1; *buf_64 = pattern; } // reverse encoding if (do_reverse) if (unlikely(cmp_extend_encoding(h, SWAP64(pattern), SWAP64(repl), idx, orig_buf, buf, len, 0, status))) return 1; } if (SHAPE_BYTES(h->shape) == 4 || *status == 2) { if (its_len >= 4 && *buf_32 == (u32)pattern) { // && *o_buf_32 == (u32)pattern) { *buf_32 = (u32)repl; if (unlikely(its_fuzz(buf, len, status))) return 1; *buf_32 = pattern; } // reverse encoding if (do_reverse) if (unlikely(cmp_extend_encoding(h, SWAP32(pattern), SWAP32(repl), idx, orig_buf, buf, len, 0, status))) return 1; } if (SHAPE_BYTES(h->shape) == 2 || *status == 2) { if (its_len >= 2 && *buf_16 == (u16)pattern) { // && *o_buf_16 == (u16)pattern) { *buf_16 = (u16)repl; if (unlikely(its_fuzz(buf, len, status))) return 1; *buf_16 = (u16)pattern; } // reverse encoding if (do_reverse) if (unlikely(cmp_extend_encoding(h, SWAP16(pattern), SWAP16(repl), idx, orig_buf, buf, len, 0, status))) return 1; } /*if (SHAPE_BYTES(h->shape) == 1 || *status == 2) { if (its_len >= 2 && *buf_8 == (u8)pattern) {// && *o_buf_8 == (u8)pattern) { *buf_8 = (u8)repl; if (unlikely(its_fuzz(buf, len, status))) return 1; *buf_16 = (u16)pattern; } }*/ return 0; } void try_to_add_to_dict(u64 v, u8 shape) { u8* b = (u8*)&v; u32 k; u8 cons_ff = 0, cons_0 = 0; for (k = 0; k < shape; ++k) { if (b[k] == 0) ++cons_0; else if (b[k] == 0xff) ++cons_0; else cons_0 = cons_ff = 0; if (cons_0 > 1 || cons_ff > 1) return; } maybe_add_auto((u8*)&v, shape); u64 rev; switch (shape) { case 1: break; case 2: rev = SWAP16((u16)v); maybe_add_auto((u8*)&rev, shape); break; case 4: rev = SWAP32((u32)v); maybe_add_auto((u8*)&rev, shape); break; case 8: rev = SWAP64(v); maybe_add_auto((u8*)&rev, shape); break; } } u8 cmp_fuzz(u32 key, u8* orig_buf, u8* buf, u32 len) { struct cmp_header* h = &cmp_map->headers[key]; u32 i, j, idx; u32 loggeds = h->hits; if (h->hits > CMP_MAP_H) loggeds = CMP_MAP_H; u8 status; // opt not in the paper u32 fails = 0; for (i = 0; i < loggeds; ++i) { struct cmp_operands* o = &cmp_map->log[key][i]; // opt not in the paper for (j = 0; j < i; ++j) if (cmp_map->log[key][j].v0 == o->v0 && cmp_map->log[key][i].v1 == o->v1) goto cmp_fuzz_next_iter; for (idx = 0; idx < len && fails < 8; ++idx) { if (unlikely(cmp_extend_encoding(h, o->v0, o->v1, idx, orig_buf, buf, len, 1, &status))) return 1; if (status == 2) ++fails; else if (status == 1) break; if (unlikely(cmp_extend_encoding(h, o->v1, o->v0, idx, orig_buf, buf, len, 1, &status))) return 1; if (status == 2) ++fails; else if (status == 1) break; } // If failed, add to dictionary if (fails == 8) { try_to_add_to_dict(o->v0, SHAPE_BYTES(h->shape)); try_to_add_to_dict(o->v1, SHAPE_BYTES(h->shape)); } cmp_fuzz_next_iter: stage_cur++; } return 0; } u8 rtn_extend_encoding(struct cmp_header* h, u8* pattern, u8* repl, u32 idx, u8* orig_buf, u8* buf, u32 len, u8* status) { u32 i; u32 its_len = MIN(32, len - idx); u8 save[32]; memcpy(save, &buf[idx], its_len); *status = 0; for (i = 0; i < its_len; ++i) { if (pattern[idx + i] != buf[idx + i] || *status == 1) break; buf[idx + i] = repl[idx + i]; if (unlikely(its_fuzz(buf, len, status))) return 1; } memcpy(&buf[idx], save, i); return 0; } u8 rtn_fuzz(u32 key, u8* orig_buf, u8* buf, u32 len) { struct cmp_header* h = &cmp_map->headers[key]; u32 i, j, idx; u32 loggeds = h->hits; if (h->hits > CMP_MAP_RTN_H) loggeds = CMP_MAP_RTN_H; u8 status; // opt not in the paper u32 fails = 0; for (i = 0; i < loggeds; ++i) { struct cmpfn_operands* o = &((struct cmpfn_operands*)cmp_map->log[key])[i]; // opt not in the paper for (j = 0; j < i; ++j) if (!memcmp(&((struct cmpfn_operands*)cmp_map->log[key])[j], o, sizeof(struct cmpfn_operands))) goto rtn_fuzz_next_iter; for (idx = 0; idx < len && fails < 8; ++idx) { if (unlikely(rtn_extend_encoding(h, o->v0, o->v1, idx, orig_buf, buf, len, &status))) return 1; if (status == 2) ++fails; else if (status == 1) break; if (unlikely(rtn_extend_encoding(h, o->v1, o->v0, idx, orig_buf, buf, len, &status))) return 1; if (status == 2) ++fails; else if (status == 1) break; } // If failed, add to dictionary if (fails == 8) { maybe_add_auto(o->v0, SHAPE_BYTES(h->shape)); maybe_add_auto(o->v1, SHAPE_BYTES(h->shape)); } rtn_fuzz_next_iter: stage_cur++; } return 0; } ///// Input to State stage // queue_cur->exec_cksum u8 input_to_state_stage(char** argv, u8* orig_buf, u8* buf, u32 len, u32 exec_cksum) { u8 r = 1; its_argv = argv; if (unlikely(colorization(buf, len, exec_cksum))) return 1; // do it manually, forkserver clear only trace_bits memset(cmp_map->headers, 0, sizeof(cmp_map->headers)); if (unlikely(common_fuzz_cmplog_stuff(argv, buf, len))) return 1; u64 orig_hit_cnt, new_hit_cnt; u64 orig_execs = total_execs; orig_hit_cnt = queued_paths + unique_crashes; stage_name = "input-to-state"; stage_short = "its"; stage_max = 0; stage_cur = 0; u32 k; for (k = 0; k < CMP_MAP_W; ++k) { if (!cmp_map->headers[k].hits) continue; if (cmp_map->headers[k].type == CMP_TYPE_INS) stage_max += MIN(cmp_map->headers[k].hits, CMP_MAP_H); else stage_max += MIN(cmp_map->headers[k].hits, CMP_MAP_RTN_H); } for (k = 0; k < CMP_MAP_W; ++k) { if (!cmp_map->headers[k].hits) continue; if (cmp_map->headers[k].type == CMP_TYPE_INS) { if (unlikely(cmp_fuzz(k, orig_buf, buf, len))) goto exit_its; } else { if (unlikely(rtn_fuzz(k, orig_buf, buf, len))) goto exit_its; } } r = 0; exit_its: memcpy(orig_buf, buf, len); new_hit_cnt = queued_paths + unique_crashes; stage_finds[STAGE_ITS] += new_hit_cnt - orig_hit_cnt; stage_cycles[STAGE_ITS] += total_execs - orig_execs; return r; }