1 /* 2 * Copyright (c) 2014-2016 Dmitry V. Levin <ldv@altlinux.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "tests.h" 29 #include <errno.h> 30 #include <fcntl.h> 31 #include <stdlib.h> 32 #include <unistd.h> 33 34 int 35 read_int_from_file(const char *const fname, int *const pvalue) 36 { 37 const int fd = open(fname, O_RDONLY); 38 if (fd < 0) 39 return -1; 40 41 long lval; 42 char buf[sizeof(lval) * 3]; 43 int n = read(fd, buf, sizeof(buf) - 1); 44 int saved_errno = errno; 45 close(fd); 46 47 if (n < 0) { 48 errno = saved_errno; 49 return -1; 50 } 51 52 buf[n] = '\0'; 53 char *endptr = 0; 54 errno = 0; 55 lval = strtol(buf, &endptr, 10); 56 if (!endptr || (*endptr && '\n' != *endptr) 57 #if INT_MAX < LONG_MAX 58 || lval > INT_MAX || lval < INT_MIN 59 #endif 60 || ERANGE == errno) { 61 if (!errno) 62 errno = EINVAL; 63 return -1; 64 } 65 66 *pvalue = (int) lval; 67 return 0; 68 } 69 70 static void 71 check_overflow_id(const int id, const char *overflowid) 72 { 73 int n; 74 75 if (read_int_from_file(overflowid, &n)) { 76 if (ENOENT == errno) 77 return; 78 perror_msg_and_fail("read_int_from_file: %s", overflowid); 79 } 80 81 if (id == n) 82 error_msg_and_skip("%d matches %s", id, overflowid); 83 } 84 85 void 86 check_overflowuid(const int uid) 87 { 88 check_overflow_id(uid, "/proc/sys/kernel/overflowuid"); 89 } 90 91 void 92 check_overflowgid(const int gid) 93 { 94 check_overflow_id(gid, "/proc/sys/kernel/overflowgid"); 95 } 96