malloc_printerr ("malloc(): memory corruption"); size = chunksize (victim); 第一句,判断bk是否指向本身或为空,若是就指向下一个chunk。 着重看一下判断条件: if (__builtin_expect (chunksize_nomask (victim) <= 2 * SIZE_SZ, 0) || __builtin_expect (chunksize_nomask (victim) > av->syst...
利用malloc consolidation 机制去在buffer中获得一个unsortedbin chunk,计算好位置,使得申请巨大内存后,切割下来的chunk刚好位于指针数组边上 通过修改 buffer,使其大小小于0xA00010且大于0x80000,使该chunk通过sort过程进入largebin 申请巨大内存得到分割后的chunk位于指针数组边上,修改指针为got['free'],向其中写入内存...
errstr ="malloc(): memory corruption (fast)"; errout:malloc_printerr(check_action, errstr,chunk2mem(victim), av);returnNULL; }check_remalloced_chunk(av, victim, nb);#ifUSE_TCACHE/* While we're here, if we see other chunks of the same size, stash them in the tcache. */size_ttc_...
errstr ="malloc(): memory corruption (fast)"; errout:malloc_printerr(check_action, errstr,chunk2mem(victim), av);returnNULL; }check_remalloced_chunk(av, victim, nb);#ifUSE_TCACHE/* While we're here, if we see other chunks of the same size, stash them in the tcache. */size_ttc_...
victim的size为0,不满足要求,触发异常,调用malloc_printerr (check_action, "malloc(): memory corruption", chunk2mem (victim), av);, 从而调用_IO_flush_all_lockp,进而fsop攻击成功。 3.2 ctf实例 - house of orange 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 lzx@ubuntu16x64:~...
malloc_printerr (check_action, "malloc(): memory corruption", chunk2mem (victim), av); size = chunksize (victim); // 当分配house3(0x20)的时候,会进入这里 if (in_smallbin_range (nb) && // 如果要申请的chunk的size在smallbin范围内 bck == unsorted_chunks (av) && // 而且bck指向main_ar...
4、改掉index 4这个堆的size域的值,以便接下来malloc到它的时候,能过malloc的检查机制。 malloc的安全检查: if(__builtin_expect(fastbin_index (chunksize (victim)) !=idx, 0)) { errstr="malloc(): memory corruption (fast)"; errout: malloc_printerr (check_action, errstr, chunk2mem (victim), ...
while((victim=unsorted_chunks(av)->bk)!=unsorted_chunks(av)){bck=victim->bk;if(__builtin_expect(chunksize_nomask(victim)<=2*SIZE_SZ,0)||__builtin_expect(chunksize_nomask(victim)>av->system_mem,0))malloc_printerr(check_action,"malloc(): memory corruption",chunk2mem(victim),av);size...
值得一提的是,堆块根据大小,libc使用fastbin、chunk等逻辑上的结构代表,但其存储结构上都是malloc_chunk结构,只是各个字段略有区别,如fastbin相对于chunk,不使用bk这个指针,因为fastbin freelist是个单向链表。 来源 Libc堆管理机制及漏洞利用技术 Malloc 源码分析 ...
/* Memory allocated from the system in this arena. */ INTERNAL_SIZE_T system_mem; INTERNAL_SIZE_T max_system_mem; }; ◆下面的代码就是定义并初始化main_arena staticstructmalloc_statemain_arena = { .mutex = _LIBC_LOCK_INITIALIZER,