1 /*- 2 * Copyright (c) 2007 Robert M. M. Watson 3 * All rights reserved. 4 * 5 * This software was developed by Robert N. M. Watson for the TrustedBSD 6 * Project. 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 30 /* 31 * Confirm that when security.bsd.unprivileged_read_msgbuf is set to 0, 32 * privilege is required to read the kernel message buffer. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/sysctl.h> 37 38 #include <err.h> 39 #include <errno.h> 40 #include <stdio.h> 41 42 #include "main.h" 43 44 #define MSGBUF_CONTROL_NAME "security.bsd.unprivileged_read_msgbuf" 45 #define MSGBUF_NAME "kern.msgbuf" 46 47 /* 48 * We must query and save the original value, then restore it when done. 49 */ 50 static int unprivileged_read_msgbuf; 51 static int unprivileged_read_msgbuf_initialized; 52 53 int 54 priv_msgbuf_privonly_setup(int asroot, int injail, struct test *test) 55 { 56 size_t len; 57 int newval; 58 59 /* 60 * Separately query and set to make debugging easier. 61 */ 62 len = sizeof(unprivileged_read_msgbuf); 63 if (sysctlbyname(MSGBUF_CONTROL_NAME, &unprivileged_read_msgbuf, 64 &len, NULL, 0) < 0) { 65 warn("priv_msgbuf_privonly_setup: sysctlbyname query"); 66 return (-1); 67 } 68 newval = 0; 69 if (sysctlbyname(MSGBUF_CONTROL_NAME, NULL, NULL, &newval, 70 sizeof(newval)) < 0) { 71 warn("priv_msgbuf_privonly_setup: sysctlbyname set"); 72 return (-1); 73 } 74 unprivileged_read_msgbuf_initialized = 1; 75 return (0); 76 } 77 78 void 79 priv_msgbuf_privonly(int asroot, int injail, struct test *test) 80 { 81 size_t len; 82 int error; 83 84 error = sysctlbyname(MSGBUF_NAME, NULL, &len, NULL, 0); 85 if (asroot && injail) 86 expect("priv_msgbuf_privonly(asroot, injail)", error, -1, 87 EPERM); 88 if (asroot && !injail) 89 expect("priv_msgbuf_privonly(asroot, !injail)", error, 0, 0); 90 if (!asroot && injail) 91 expect("priv_msgbuf_privonly(!asroot, injail)", error, -1, 92 EPERM); 93 if (!asroot && !injail) 94 expect("priv_msgbuf_privonly(!asroot, !injail)", error, -1, 95 EPERM); 96 } 97 98 int 99 priv_msgbuf_unprivok_setup(int asroot, int injail, struct test *test) 100 { 101 size_t len; 102 int newval; 103 104 /* 105 * Separately query and set to make debugging easier. 106 */ 107 len = sizeof(unprivileged_read_msgbuf); 108 if (sysctlbyname(MSGBUF_CONTROL_NAME, &unprivileged_read_msgbuf, &len, 109 NULL, 0) < 0) { 110 warn("priv_msgbuf_unprivok_setup: sysctlbyname query"); 111 return (-1); 112 } 113 newval = 1; 114 if (sysctlbyname(MSGBUF_CONTROL_NAME, NULL, NULL, &newval, 115 sizeof(newval)) < 0) { 116 warn("priv_msgbuf_unprivok_setup: sysctlbyname set"); 117 return (-1); 118 } 119 unprivileged_read_msgbuf_initialized = 1; 120 return (0); 121 } 122 123 void 124 priv_msgbuf_unprivok(int asroot, int injail, struct test *test) 125 { 126 size_t len; 127 int error; 128 129 error = sysctlbyname(MSGBUF_NAME, NULL, &len, NULL, 0); 130 if (asroot && injail) 131 expect("priv_msgbuf_unprivok(asroot, injail)", error, 0, 0); 132 if (asroot && !injail) 133 expect("priv_msgbuf_unprivok(asroot, !injail)", error, 0, 0); 134 if (!asroot && injail) 135 expect("priv_msgbuf_unprivok(!asroot, injail)", error, 0, 0); 136 if (!asroot && !injail) 137 expect("priv_msgbuf_unprivok(!asroot, !injail)", error, 0, 0); 138 } 139 140 void 141 priv_msgbuf_cleanup(int asroot, int injail, struct test *test) 142 { 143 144 if (unprivileged_read_msgbuf_initialized) { 145 (void)sysctlbyname(MSGBUF_NAME, NULL, NULL, 146 &unprivileged_read_msgbuf, 147 sizeof(unprivileged_read_msgbuf)); 148 unprivileged_read_msgbuf_initialized = 0; 149 } 150 } 151