1 /*- 2 * Copyright (c) 2006 nCircle Network Security, Inc. 3 * All rights reserved. 4 * 5 * This software was developed by Robert N. M. Watson for the TrustedBSD 6 * Project under contract to nCircle Network Security, Inc. 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 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY, 21 * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 23 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 24 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 25 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 26 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 /* 33 * Test that privilege is required to lower nice value; first test with, then 34 * without. There are two failure modes associated with privilege: the right 35 * to renice a process with a different uid, and the right to renice to a 36 * lower priority. Because both the real and effective uid are part of the 37 * permissions test, we have to create two children processes with different 38 * uids. 39 */ 40 41 #include <sys/types.h> 42 #include <sys/resource.h> 43 #include <sys/wait.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <signal.h> 48 #include <stdlib.h> 49 #include <unistd.h> 50 51 #include "main.h" 52 53 static void 54 dummy(void) 55 { 56 57 while (1) 58 sleep(1); 59 } 60 61 static void 62 collect(pid_t test_pid, pid_t dummy_pid) 63 { 64 pid_t pid; 65 66 /* 67 * First, collect the main test process. When it has exited, then 68 * kill off the dummy process. 69 */ 70 if (test_pid > 0) { 71 while (1) { 72 pid = waitpid(test_pid, NULL, 0); 73 if (pid == -1) 74 warn("waitpid(%d (test), NULL, 0)", test_pid); 75 if (pid == test_pid) 76 break; 77 } 78 } 79 80 if (kill(dummy_pid, SIGKILL) < 0) 81 err(-1, "kill(%d, SIGKILL)", dummy_pid); 82 83 while (1) { 84 pid = waitpid(dummy_pid, NULL, 0); 85 if (pid == -1) 86 warn("waitpid(%d, NULL, 0)", dummy_pid); 87 if (pid == dummy_pid) 88 return; 89 } 90 } 91 92 static void 93 test(pid_t dummy_pid) 94 { 95 int error; 96 97 /* 98 * Tests first as root. 99 */ 100 if (setpriority(PRIO_PROCESS, 0, -1) < 0) 101 err(-1, "setpriority(PRIO_PROCESS, 0, -1) as root"); 102 103 if (setpriority(PRIO_PROCESS, dummy_pid, -1) < 0) 104 err(-1, "setpriority(PRIO_PROCESS, %d, -1) as root", 105 dummy_pid); 106 107 /* 108 * Then test again as a different credential. 109 */ 110 if (setresuid(UID_OTHER, UID_OTHER, UID_OTHER) < 0) 111 err(-1, "setresuid(%d)", UID_OTHER); 112 113 error = setpriority(PRIO_PROCESS, 0, -2); 114 if (error == 0) 115 errx(-1, 116 "setpriority(PRIO_PROCESS, 0, -2) succeeded as !root"); 117 if (errno != EACCES) 118 err(-1, "setpriority(PRIO_PROCESS, 0, 2) wrong errno %d as " 119 "!root", errno); 120 121 error = setpriority(PRIO_PROCESS, dummy_pid, -2); 122 if (error == 0) 123 errx(-1, 124 "setpriority(PRIO_PROCESS, %d, -2) succeeded as !root", 125 dummy_pid); 126 if (errno != EPERM) 127 err(-1, "setpriority(PRIO_PROCESS, %d, 2) wrong errno %d as " 128 "!root", dummy_pid, errno); 129 130 exit(0); 131 } 132 133 void 134 priv_sched_setpriority(void) 135 { 136 pid_t dummy_pid, test_pid; 137 138 assert_root(); 139 140 /* 141 * Set up dummy process, which we will kill before exiting. 142 */ 143 dummy_pid = fork(); 144 if (dummy_pid < 0) 145 err(-1, "fork - dummy"); 146 if (dummy_pid == 0) { 147 if (setresuid(UID_THIRD, UID_THIRD, UID_THIRD) < 0) 148 err(-1, "setresuid(%d)", UID_THIRD); 149 dummy(); 150 } 151 sleep(1); /* Allow dummy thread to change uids. */ 152 153 test_pid = fork(); 154 if (test_pid < 0) { 155 warn("fork - test"); 156 collect(-1, dummy_pid); 157 return; 158 } 159 if (test_pid == 0) 160 test(dummy_pid); 161 162 collect(test_pid, dummy_pid); 163 } 164