https://re-st.github.io/blog/afl/Recent content in AFL on Park, Geon (re-st)Hugoko-krCopyright © 2026, Geon Park.Wed, 29 Apr 2026 14:28:04 +0900https://re-st.github.io/log/afl-afl-%EC%86%8C%EC%8A%A4%EC%BD%94%EB%93%9C-%EC%88%98%EC%A0%95-%EC%8B%9C-%EB%94%94%EB%B2%84%EA%B9%85-gdb-%EC%82%AC%EC%9A%A9/Mon, 06 Oct 2025 21:27:24 +0900https://re-st.github.io/log/afl-afl-%EC%86%8C%EC%8A%A4%EC%BD%94%EB%93%9C-%EC%88%98%EC%A0%95-%EC%8B%9C-%EB%94%94%EB%B2%84%EA%B9%85-gdb-%EC%82%AC%EC%9A%A9/GDB로 afl-fuzz 내부 크래시 파헤치기https://re-st.github.io/log/afl-afl-%EB%94%94%EB%B2%84%EA%B9%85-setaffinity-%EB%AC%B8%EC%A0%9C%EC%99%80-%ED%95%B4%EA%B2%B0-bind_to_free_cpu%EC%97%90%EC%84%9C-%EC%97%90%EB%9F%AC/Mon, 22 Sep 2025 12:00:00 +0900https://re-st.github.io/log/afl-afl-%EB%94%94%EB%B2%84%EA%B9%85-setaffinity-%EB%AC%B8%EC%A0%9C%EC%99%80-%ED%95%B4%EA%B2%B0-bind_to_free_cpu%EC%97%90%EC%84%9C-%EC%97%90%EB%9F%AC/<p><strong>문제 예시</strong></p> <div class="highlight"><pre tabindex="0" style="background-color:#f0f0f0;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 1</span><span>&gt; ./afl-fuzz <span style="color:#666">(</span>후략<span style="color:#666">)</span> </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 2</span><span>afl-fuzz 2.57b by &lt;lcamtuf@google.com&gt; </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 3</span><span><span style="color:#666">[</span>+<span style="color:#666">]</span> You have <span style="color:#40a070">64</span> CPU cores and <span style="color:#40a070">2</span> runnable tasks <span style="color:#666">(</span>utilization: 3%<span style="color:#666">)</span>. </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 4</span><span><span style="color:#666">[</span>+<span style="color:#666">]</span> Try parallel <span style="color:#007020">jobs</span> - see docs/parallel_fuzzing.txt. </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 5</span><span><span style="color:#666">[</span>*<span style="color:#666">]</span> Checking CPU core loadout... </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 6</span><span><span style="color:#666">[</span>+<span style="color:#666">]</span> Found a free CPU core, binding to <span style="color:#60a0b0;font-style:italic">#0.</span> </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 7</span><span> </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 8</span><span><span style="color:#666">[</span>-<span style="color:#666">]</span> SYSTEM ERROR : sched_setaffinity failed </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f"> 9</span><span> Stop location : bind_to_free_cpu<span style="color:#666">()</span>, afl-fuzz.c:1134 </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">10</span><span> OS message : Invalid argument </span></span></code></pre></div><p><strong>해결</strong> 이를 우회하기 위한 환경변수인 <code>AFL_NO_AFFINITY</code>를 설정한다.</p>https://re-st.github.io/howto/afl-afl-%EB%94%94%EB%B2%84%EA%B9%85-asan%EC%9C%BC%EB%A1%9C-instrument%ED%95%98%EA%B3%A0-%EB%8F%8C%EB%A6%AC%EA%B8%B0/Wed, 03 Sep 2025 14:00:00 +0900https://re-st.github.io/howto/afl-afl-%EB%94%94%EB%B2%84%EA%B9%85-asan%EC%9C%BC%EB%A1%9C-instrument%ED%95%98%EA%B3%A0-%EB%8F%8C%EB%A6%AC%EA%B8%B0/<p>목차</p> <ol> <li>AFL</li> <li>AFL++</li> <li>입힌 뒤 확인</li> </ol> <h1 id="afl---makefile의-cflags를-수정한다">AFL - Makefile의 CFLAGS를 수정한다.</h1> <p>Makefile의 CFLAGS부분에 <code>-fsanitize=address</code>을 추가한다.</p> <div class="highlight"><pre tabindex="0" style="background-color:#f0f0f0;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-Makefile" data-lang="Makefile"><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">1</span><span><span style="color:#bb60d5">CFLAGS</span>     <span style="color:#666">+=</span> -fsanitize<span style="color:#666">=</span>address -Wall -D_FORTIFY_SOURCE<span style="color:#666">=</span><span style="color:#40a070">2</span> -g -Wno-pointer-sign <span style="color:#4070a0;font-weight:bold">\ </span></span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">2</span><span> </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">3</span><span>        <span style="color:#bb60d5">-DAFL_PATH</span><span style="color:#666">=</span><span style="color:#4070a0;font-weight:bold">\&#34;\(</span><span style="color:#666">(</span>HELPER_PATH<span style="color:#666">)</span><span style="color:#4070a0;font-weight:bold">\&#34;</span> -DDOC_PATH<span style="color:#666">=</span><span style="color:#4070a0;font-weight:bold">\&#34;\)</span><span style="color:#666">(</span>DOC_PATH<span style="color:#666">)</span><span style="color:#4070a0;font-weight:bold">\&#34;</span> <span style="color:#4070a0;font-weight:bold">\ </span></span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">4</span><span> </span></span><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">5</span><span>        <span style="color:#bb60d5">-DBIN_PATH</span><span style="color:#666">=</span><span style="color:#4070a0;font-weight:bold">\&#34;</span><span style="color:#007020;font-weight:bold">$(</span>BIN_PATH<span style="color:#007020;font-weight:bold">)</span><span style="color:#4070a0;font-weight:bold">\&#34;</span> </span></span></code></pre></div><h2 id="실패담">실패담</h2> <p><code>export AFL_USE_ASAN=1</code> 은 왜인지 먹지 않는다.</p> <h1 id="afl---asan_build-환경변수를-설정한다">AFL++ - ASAN_BUILD 환경변수를 설정한다.</h1> <div class="highlight"><pre tabindex="0" style="background-color:#f0f0f0;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#7f7f7f">1</span><span><span style="color:#007020">cd</span> ./AFLplusplus <span style="color:#666">&amp;&amp;</span> <span style="color:#bb60d5">ASAN_BUILD</span><span style="color:#666">=</span><span style="color:#4070a0">&#34;1&#34;</span> make clean all </span></span></code></pre></div><h2 id="asan-crashlog에-줄-번호가-나오지-않을-것이다-addr2line을-쓰자">ASAN crashlog에 줄 번호가 나오지 않을 것이다. addr2line을 쓰자.</h2> <p>ASAN crashlog에 나온 포인터를 addr2line으로 확인한다.</p>https://re-st.github.io/essay/implementation-on-afl-has-cons-too/Thu, 24 Jul 2025 00:00:00 +0900https://re-st.github.io/essay/implementation-on-afl-has-cons-too/<p><a href="https://re-st.github.io/category/%EB%82%B4-%EC%97%90%EC%84%B8%EC%9D%B4/">[분류] 에세이</a></p>https://re-st.github.io/research/trace_bits/Mon, 01 Jul 2024 12:00:00 +0900https://re-st.github.io/research/trace_bits/AFL 퍼징이 사용하는 매 실행 커버리지 기록 도구https://re-st.github.io/research/virgin_bits/Mon, 24 Jun 2024 12:00:00 +0900https://re-st.github.io/research/virgin_bits/AFL 퍼징이 사용하는 역대 실행 커버리지 기록 도구https://re-st.github.io/research/%ED%8D%BC%EC%A7%95%EC%97%90%EC%84%9C%EC%9D%98-%ED%81%90-%EC%BB%AC%EB%A7%81-%EC%9D%B8%ED%92%8B-%EC%A4%84%EC%84%B8%EC%9A%B0%EA%B8%B0/Fri, 01 Sep 2023 12:00:00 +0900https://re-st.github.io/research/%ED%8D%BC%EC%A7%95%EC%97%90%EC%84%9C%EC%9D%98-%ED%81%90-%EC%BB%AC%EB%A7%81-%EC%9D%B8%ED%92%8B-%EC%A4%84%EC%84%B8%EC%9A%B0%EA%B8%B0/퍼징에서 다음 시드를 선택하는 알고리즘