{"id":100,"date":"2026-04-27T22:27:13","date_gmt":"2026-04-27T14:27:13","guid":{"rendered":"http:\/\/39.106.187.170\/?p=100"},"modified":"2026-04-27T22:27:13","modified_gmt":"2026-04-27T14:27:13","slug":"%e3%80%90pwn%e3%80%91%e5%a0%86%e5%ad%a6%e4%b9%a0%e4%b9%8bglibc2-31%e4%b8%8b%e7%9a%84tcache%e6%9c%ba%e5%88%b6","status":"publish","type":"post","link":"http:\/\/39.106.187.170\/index.php\/2026\/04\/27\/%e3%80%90pwn%e3%80%91%e5%a0%86%e5%ad%a6%e4%b9%a0%e4%b9%8bglibc2-31%e4%b8%8b%e7%9a%84tcache%e6%9c%ba%e5%88%b6\/","title":{"rendered":"\u3010Pwn\u3011\u5806\u5b66\u4e60\u4e4bglibc2.31\u4e0b\u7684tcache\u673a\u5236\u00a0"},"content":{"rendered":"\n

0x2 tcache\u673a\u5236<\/h2>\n\n\n\n

  0x1 tcache\u662f\u4ec0\u4e48<\/h3>\n\n\n\n

    \u00b7<\/strong> tcache\u662f\u6ee1\u8db3\u4e00\u5b9a\u6761\u4ef6\u7684chunk\u88abfree\u540e\u9996\u5148\u8fdb\u5165\u7684bin\uff0c\u57282.31\u7248\u672c\u4e2d\u4e00\u4e2atcachebin\u6700\u591a\u5b58\u50a87\u4e2achunk\uff0c\u4f7f\u7528\u5355\u94fe\u8868<\/strong>\uff0c\u5934\u63d2\u6cd5<\/strong>\u3002\u572864\u4f4d\u7cfb\u7edf\u4e0b\uff0c\u4e0d\u540c\u7684tcachebin\u53ef\u5b58\u50a8\u7684chunk\u7684\u5927\u5c0f\u8303\u56f4\u5982\u4e0b\uff1aidx0\u5bf9\u5e940-24\u5b57\u8282\uff0cidx1\u5bf9\u5e9425-40\u5b57\u8282\uff0cidx2\u5bf9\u5e9441-56\u5b57\u8282\u3002<\/p>\n\n\n\n

  0x2 chunk\u8fdb\u5165tcache\u7684\u53d8\u5316<\/h3>\n\n\n\n

  \u00b7<\/strong> chunk\u8fdb\u5165tcache\u540e\uff0cuser_data\u7684\u524d\u4e24\u4e2a\u69fd\u4f4d\u4f1a\u53d1\u751f\u53d8\u5316\u3002user_data+0x00\u5199\u4e3anext\uff0c\u6307\u5411tcache\u94fe\u8868\u4e2d\u7684\u4e0b\u4e00\u4e2achunk\uff0c\u5982\u679c\u94fe\u8868\u4e3a\u7a7a\u5219next\u4e5f\u4e3anull\uff1buser_data+0x08\u5199\u4e3akey\uff0c\u6307\u5411\u5f53\u524d\u7ebf\u7a0b\u7684tcache\uff0c\u6807\u5fd7\u5f53\u524dchunk\u4f4d\u4e8etcache\u94fe\u8868\u4e2d\uff0c\u4e5f\u7528\u4e8e\u8f85\u52a9double free\u68c0\u6d4b\u3002\u5f53\u524dbin\u7684\u5934\u8282\u70b9\u4f1a\u6307\u5411\u65b0\u8fdb\u5165\u7684chunk\u3002\u6ce8\u610f\uff1achunk\u8fdb\u5165tcache\u94fe\u8868\u65f6\u5e76\u4e0d\u662f\u6574\u4e2achunk\u5728\u5185\u5b58\u7a7a\u95f4\u4e2d\u79fb\u52a8\uff0c\u800c\u662fuser_data\u7684\u524d\u4e24\u4e2a\u69fd\u4f4d\u53d1\u751f\u53d8\u5316\u3002chunk\u8fdb\u5165tcache\u7684\u903b\u8f91\u7531tcache_put\u51fd\u6570\u8d1f\u8d23\u3002<\/p>\n\n\n\n

  0x3 chunk\u79bb\u5f00tcache\u7684\u53d8\u5316<\/h3>\n\n\n\n

  \u00b7<\/strong> chunk\u79bb\u5f00\u65f6\uff0c\u5f53\u524dbin\u5934\u8282\u70b9\u6307\u5411next\uff0c\u5373\u4e0b\u4e00\u4e2achunk\u7684user_data\u5934\u3002key\u88ab\u6e05\u7a7a\uff0c\u6807\u5fd7chunk\u88ab\u4f7f\u7528\u3002<\/p>\n\n\n\n

  0x4 tcache\u5b9e\u4f8b<\/h3>\n\n\n\n

  \u00b7<\/strong> \u4f7f\u7528\u5982\u4e0b\u5b9e\u4f8b\uff1a<\/p>\n\n\n\n

#include <stdio.h>\n#include <stdlib.h>\n\nint main() {\n    setbuf(stdout, NULL);\n\n    char *a = malloc(0x20);\n    char *b = malloc(0x20);\n\n    printf(\"a = %p\\n\", a);\n    printf(\"b = %p\\n\", b);\n\n    free(a);\n    free(b);\n\n    char *c = malloc(0x20);\n    char *d = malloc(0x20);\n\n    printf(\"c = %p\\n\", c);\n    printf(\"d = %p\\n\", d);\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
\u00a0\u00a0\u00b7<\/strong> \u4e24\u6b21malloc\u540echunk\u72b6\u6001\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
  \u00b7<\/strong> free(a)\u540e\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
  \u53ef\u4ee5\u770b\u5230a\u786e\u5b9e\u8fdb\u5165\u4e86tcache\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
  \u53ef\u4ee5\u770b\u5230user_data+0x08\u53d8\u6210\u4e86\u6307\u9488\u4e00\u6837\u7684\u4e1c\u897f\uff0c\u5373key\uff0c\u6307\u5411tcache\u3002<\/p>\n\n\n\n
  \u00b7<\/strong> free(b)\u540e\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
  \u53ef\u4ee5\u770b\u5230a\u4e0eb\u6b64\u65f6\u90fd\u5728tcache\u4e2d\uff0cb\u7684user_data\u7684\u524d\u4e24\u4e2a\u69fd\u4f4d\u4e5f\u90fd\u53d8\u6210\u4e86\u6307\u9488\uff0c\u5176\u4e2duser_data+0x00\u53d8\u4e3anext\uff0c\u6307\u5411a\u7684user_date\uff0cuser_data+0x08\u53d8\u4e3akey\uff0c\u6307\u5411tcache\u3002\u6b64\u65f6a\u4e0eb\u7684\u4f4d\u7f6e\u72b6\u6001\u5982\u4e0b\uff1a<\/p>\n\n\n\n
  head–>b–>a–>NULL<\/p>\n\n\n\n
  \u00b7<\/strong> char *c = malloc(0x20)\u540e\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
  \u53ef\u4ee5\u770b\u5230b\u5df2\u7ecf\u4ece\u94fe\u8868\u4e2d\u5f39\u51fa\uff0c\u4e14key\u88ab\u6e05\u9664\uff0c\u6807\u5fd7\u8be5chunk\u5df2\u79bb\u5f00\u94fe\u8868\u3002<\/p>\n\n\n\n
  \u00b7<\/strong> tcache\u88ab\u585e\u6ee1\u7684\u60c5\u51b5\uff08\u4f7f\u7528\u5982\u4e0b\u5b9e\u4f8b\uff09\uff1a<\/p>\n\n\n\n
#include <stdio.h> \n#include <stdlib.h> \n\nint main() { \n    setbuf(stdout, NULL); \n\n    char *a = malloc(0x20); \n    char *b = malloc(0x20); \n    char *c = malloc(0x20); \n    char *d = malloc(0x20); \n    char *e = malloc(0x20); \n    char *f = malloc(0x20); \n    char *g = malloc(0x20); \n    char *h = malloc(0x20); \n\n\n    free(a); \n    free(b); \n    free(c); \n    free(d); \n    free(e); \n    free(f); \n    free(g); \n    free(h); \n\n    return 0; \n}<\/code><\/pre>\n\n\n\n
  \u00b7<\/strong> 8\u6b21free\u540e\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
  \u53ef\u4ee5\u770b\u5230\u5b58\u50a80x30\u5927\u5c0f\u7684tcachebin\u88ab\u586b\u6ee1\uff0c\u6700\u591a\u5b58\u50a87\u4e2achunk\uff0c\u7b2c8\u4e2achunk\u8fdb\u5165fastbin\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
0x2 tcache\u673a\u5236   0x1 tcache\u662f\u4ec0\u4e48   &nbs\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-100","post","type-post","status-publish","format-standard","hentry","category-heap2-31"],"_links":{"self":[{"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/posts\/100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/comments?post=100"}],"version-history":[{"count":1,"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/posts\/100\/revisions"}],"predecessor-version":[{"id":107,"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/posts\/100\/revisions\/107"}],"wp:attachment":[{"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/media?parent=100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/categories?post=100"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/39.106.187.170\/index.php\/wp-json\/wp\/v2\/tags?post=100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}