1 /* 2 * Check decoding of chown/chown32/lchown/lchown32/fchown/fchown32 syscalls. 3 * 4 * Copyright (c) 2016 Dmitry V. Levin <ldv (at) altlinux.org> 5 * Copyright (c) 2016-2017 The strace developers. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <fcntl.h> 32 #include <stdio.h> 33 #include <unistd.h> 34 35 #ifdef UGID_TYPE_IS_SHORT 36 # define UGID_TYPE short 37 # define GETEUID syscall(__NR_geteuid) 38 # define GETEGID syscall(__NR_getegid) 39 # define CHECK_OVERFLOWUID(arg) check_overflowuid(arg) 40 # define CHECK_OVERFLOWGID(arg) check_overflowgid(arg) 41 #else 42 # define UGID_TYPE int 43 # define GETEUID geteuid() 44 # define GETEGID getegid() 45 # define CHECK_OVERFLOWUID(arg) 46 # define CHECK_OVERFLOWGID(arg) 47 #endif 48 49 #define UNLINK_SAMPLE \ 50 do { \ 51 if (unlink(sample)) \ 52 perror_msg_and_fail("unlink"); \ 53 } while (0) 54 55 #define CLOSE_SAMPLE \ 56 do { \ 57 if (close(fd)) \ 58 perror_msg_and_fail("close"); \ 59 } while (0) 60 61 #ifdef ACCESS_BY_DESCRIPTOR 62 # define SYSCALL_ARG1 fd 63 # define FMT_ARG1 "%d" 64 # define EOK_CMD CLOSE_SAMPLE 65 # define CLEANUP_CMD UNLINK_SAMPLE 66 #else 67 # define SYSCALL_ARG1 sample 68 # define FMT_ARG1 "\"%s\"" 69 # define EOK_CMD UNLINK_SAMPLE 70 # define CLEANUP_CMD CLOSE_SAMPLE 71 #endif 72 73 static int 74 ugid2int(const unsigned UGID_TYPE id) 75 { 76 if ((unsigned UGID_TYPE) -1U == id) 77 return -1; 78 else 79 return id; 80 } 81 82 static void 83 print_int(const unsigned int num) 84 { 85 if (num == -1U) 86 printf(", -1"); 87 else 88 printf(", %u", num); 89 } 90 91 static int 92 num_matches_id(const unsigned int num, const unsigned int id) 93 { 94 return num == id || num == -1U; 95 } 96 97 #define PAIR(val) { val, gid }, { uid, val } 98 99 int 100 main(void) 101 { 102 static const char sample[] = SYSCALL_NAME "_sample"; 103 104 unsigned int uid = GETEUID; 105 CHECK_OVERFLOWUID(uid); 106 unsigned int gid = GETEGID; 107 CHECK_OVERFLOWUID(gid); 108 109 const struct { 110 const long uid, gid; 111 } tests[] = { 112 { uid, gid }, 113 { (unsigned long) 0xffffffff00000000ULL | uid, gid }, 114 { uid, (unsigned long) 0xffffffff00000000ULL | gid }, 115 PAIR(-1U), 116 PAIR(-1L), 117 { 0xffff0000U | uid, gid }, 118 { uid, 0xffff0000U | gid }, 119 PAIR(0xffff), 120 PAIR(0xc0deffffU), 121 PAIR(0xfacefeedU), 122 PAIR((long) 0xfacefeeddeadbeefULL) 123 }; 124 125 int fd = open(sample, O_RDONLY | O_CREAT, 0400); 126 if (fd < 0) 127 perror_msg_and_fail("open"); 128 129 CLEANUP_CMD; 130 131 unsigned int i; 132 long expected = 0; 133 134 for (i = 0; i < ARRAY_SIZE(tests); ++i) { 135 const unsigned int unum = ugid2int(tests[i].uid); 136 const unsigned int gnum = ugid2int(tests[i].gid); 137 138 if (num_matches_id(unum, uid) && 139 num_matches_id(gnum, gid)) { 140 if (expected) 141 continue; 142 } else { 143 if (!expected) { 144 expected = -1; 145 EOK_CMD; 146 } 147 } 148 149 const long rc = syscall(SYSCALL_NR, SYSCALL_ARG1, 150 tests[i].uid, tests[i].gid); 151 const char *errstr = sprintrc(rc); 152 printf("%s(" FMT_ARG1, SYSCALL_NAME, SYSCALL_ARG1); 153 print_int(unum); 154 print_int(gnum); 155 printf(") = %s\n", errstr); 156 } 157 158 puts("+++ exited with 0 +++"); 159 return 0; 160 } 161
