| /* |
| * Copyright (C) 2012 Red Hat, Inc. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of version 2 of the GNU General Public |
| * License as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| * |
| * Further, this software is distributed without any warranty that it |
| * is free of the rightful claim of any third person regarding |
| * infringement or the like. Any license provided herein, whether |
| * implied or otherwise, applies only to this software file. Patent |
| * licenses, if any, provided herein do not apply to combinations of |
| * this program with other software, or any other product whatsoever. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| * 02110-1301, USA. |
| */ |
| /* |
| * This is a reproducer for CVE-2011-2496. |
| * |
| * The normal mmap paths all avoid creating a mapping where the pgoff |
| * inside the mapping could wrap around due to overflow. However, an |
| * expanding mremap() can take such a non-wrapping mapping and make it |
| * bigger and cause a wrapping condition. There is also another case |
| * where we expand mappings hiding in plain sight: the automatic stack |
| * expansion. |
| * |
| * This program tries to remap a mapping with a new size that would |
| * wrap pgoff. Notice that it only works on 32-bit arch for now. |
| */ |
| |
| #define _GNU_SOURCE |
| #include "config.h" |
| #include <sys/types.h> |
| #include <sys/mman.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| |
| #include "test.h" |
| |
| char *TCID = "vma03"; |
| int TST_TOTAL = 1; |
| |
| #ifdef __NR_mmap2 |
| #define TESTFILE "testfile" |
| |
| static size_t pgsz; |
| static int fd; |
| |
| static void *mmap2(void *addr, size_t length, int prot, |
| int flags, int fd, off_t pgoffset); |
| static void setup(void); |
| static void cleanup(void); |
| |
| int main(int argc, char *argv[]) |
| { |
| const char *msg; |
| int lc; |
| void *map, *remap; |
| off_t pgoff; |
| |
| #if __WORDSIZE != 32 |
| tst_brkm(TCONF, NULL, "test is designed for 32-bit system only."); |
| #endif |
| msg = parse_opts(argc, argv, NULL, NULL); |
| if (msg != NULL) |
| tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg); |
| |
| pgsz = sysconf(_SC_PAGE_SIZE); |
| setup(); |
| |
| for (lc = 0; TEST_LOOPING(lc); lc++) { |
| tst_count = 0; |
| |
| fd = open(TESTFILE, O_RDWR); |
| if (fd == -1) |
| tst_brkm(TBROK | TERRNO, NULL, "open %s", TESTFILE); |
| |
| pgoff = ULONG_MAX - 1; |
| map = mmap2(NULL, pgsz, PROT_READ | PROT_WRITE, MAP_PRIVATE, |
| fd, pgoff); |
| if (map == MAP_FAILED) |
| tst_brkm(TBROK | TERRNO, cleanup, "mmap2"); |
| |
| remap = mremap(map, pgsz, 2 * pgsz, 0); |
| if (remap == MAP_FAILED) { |
| if (errno == EINVAL) |
| tst_resm(TPASS, "mremap failed as expected."); |
| else |
| tst_resm(TFAIL | TERRNO, "mremap"); |
| munmap(map, pgsz); |
| } else { |
| tst_resm(TFAIL, "mremap succeeded unexpectedly."); |
| munmap(remap, 2 * pgsz); |
| } |
| |
| close(fd); |
| } |
| |
| cleanup(); |
| tst_exit(); |
| } |
| |
| static void *mmap2(void *addr, size_t length, int prot, |
| int flags, int fd, off_t pgoffset) |
| { |
| return (void *)syscall(SYS_mmap2, addr, length, prot, |
| flags, fd, pgoffset); |
| } |
| |
| static void setup(void) |
| { |
| tst_sig(FORK, DEF_HANDLER, cleanup); |
| |
| tst_tmpdir(); |
| |
| fd = creat(TESTFILE, 0644); |
| if (fd == -1) |
| tst_brkm(TBROK | TERRNO, NULL, "creat %s", TESTFILE); |
| close(fd); |
| |
| TEST_PAUSE; |
| } |
| |
| static void cleanup(void) |
| { |
| tst_rmdir(); |
| } |
| #else /* __NR_mmap2 */ |
| int main(int argc, char *argv[]) |
| { |
| tst_brkm(TCONF, NULL, "__NR_mmap2 is not defined on your system"); |
| } |
| #endif |