Jorge Lucangeli Obes | d613ab2 | 2015-03-03 14:22:50 -0800 | [diff] [blame] | 1 | /* Copyright (c) 2012 The Chromium OS Authors. All rights reserved. |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2 | * Use of this source code is governed by a BSD-style license that can be |
Will Drewry | 32ac9f5 | 2011-08-18 21:36:27 -0500 | [diff] [blame] | 3 | * found in the LICENSE file. |
| 4 | */ |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 5 | |
| 6 | #define _BSD_SOURCE |
Arthur Gautier | 7a56907 | 2016-04-23 17:25:20 +0000 | [diff] [blame] | 7 | #define _DEFAULT_SOURCE |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 8 | #define _GNU_SOURCE |
Jorge Lucangeli Obes | c2c9bcc | 2012-05-01 09:30:24 -0700 | [diff] [blame] | 9 | |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 10 | #include <asm/unistd.h> |
Luis Hector Chavez | 43ff080 | 2016-10-07 12:21:07 -0700 | [diff] [blame] | 11 | #include <dirent.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 12 | #include <errno.h> |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 13 | #include <fcntl.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 14 | #include <grp.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 15 | #include <linux/capability.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 16 | #include <pwd.h> |
| 17 | #include <sched.h> |
| 18 | #include <signal.h> |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 19 | #include <stdbool.h> |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 20 | #include <stddef.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 21 | #include <stdio.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 24 | #include <sys/capability.h> |
| 25 | #include <sys/mount.h> |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 26 | #include <sys/param.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 27 | #include <sys/prctl.h> |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 28 | #include <sys/stat.h> |
| 29 | #include <sys/types.h> |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 30 | #include <sys/user.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 31 | #include <sys/wait.h> |
Luis Hector Chavez | fb449ab | 2016-10-14 09:49:22 -0700 | [diff] [blame] | 32 | #include <syscall.h> |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 33 | #include <unistd.h> |
| 34 | |
| 35 | #include "libminijail.h" |
| 36 | #include "libminijail-private.h" |
| 37 | |
Jorge Lucangeli Obes | a21c8fc | 2015-07-15 16:22:34 -0700 | [diff] [blame] | 38 | #include "signal_handler.h" |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 39 | #include "syscall_filter.h" |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 40 | #include "syscall_wrapper.h" |
Jorge Lucangeli Obes | 0b20877 | 2017-04-19 14:15:46 -0400 | [diff] [blame] | 41 | #include "system.h" |
Jorge Lucangeli Obes | a6b034d | 2012-08-07 15:29:20 -0700 | [diff] [blame] | 42 | #include "util.h" |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 43 | |
Jorge Lucangeli Obes | f783b52 | 2016-03-14 14:34:10 -0700 | [diff] [blame] | 44 | /* Until these are reliably available in linux/prctl.h. */ |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 45 | #ifndef PR_ALT_SYSCALL |
| 46 | # define PR_ALT_SYSCALL 0x43724f53 |
| 47 | #endif |
| 48 | |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 49 | /* Seccomp filter related flags. */ |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 50 | #ifndef PR_SET_NO_NEW_PRIVS |
| 51 | # define PR_SET_NO_NEW_PRIVS 38 |
| 52 | #endif |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 53 | |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 54 | #ifndef SECCOMP_MODE_FILTER |
Jorge Lucangeli Obes | 0b20877 | 2017-04-19 14:15:46 -0400 | [diff] [blame] | 55 | #define SECCOMP_MODE_FILTER 2 /* Uses user-supplied filter. */ |
Will Drewry | 32ac9f5 | 2011-08-18 21:36:27 -0500 | [diff] [blame] | 56 | #endif |
| 57 | |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 58 | #ifndef SECCOMP_SET_MODE_STRICT |
| 59 | # define SECCOMP_SET_MODE_STRICT 0 |
| 60 | #endif |
| 61 | #ifndef SECCOMP_SET_MODE_FILTER |
| 62 | # define SECCOMP_SET_MODE_FILTER 1 |
| 63 | #endif |
| 64 | |
| 65 | #ifndef SECCOMP_FILTER_FLAG_TSYNC |
| 66 | # define SECCOMP_FILTER_FLAG_TSYNC 1 |
| 67 | #endif |
| 68 | /* End seccomp filter related flags. */ |
| 69 | |
Dylan Reid | 4cbc2a5 | 2016-06-17 19:06:07 -0700 | [diff] [blame] | 70 | /* New cgroup namespace might not be in linux-headers yet. */ |
| 71 | #ifndef CLONE_NEWCGROUP |
| 72 | # define CLONE_NEWCGROUP 0x02000000 |
| 73 | #endif |
| 74 | |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 75 | #define MAX_CGROUPS 10 /* 10 different controllers supported by Linux. */ |
| 76 | |
Chirantan Ekbote | 866bb3a | 2017-02-07 12:26:42 -0800 | [diff] [blame] | 77 | /* Keyctl commands. */ |
| 78 | #define KEYCTL_JOIN_SESSION_KEYRING 1 |
| 79 | |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 80 | struct mountpoint { |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 81 | char *src; |
| 82 | char *dest; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 83 | char *type; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 84 | char *data; |
| 85 | int has_data; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 86 | unsigned long flags; |
| 87 | struct mountpoint *next; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 88 | }; |
| 89 | |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 90 | struct minijail { |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 91 | /* |
Jorge Lucangeli Obes | c8b21e1 | 2014-06-13 14:26:16 -0700 | [diff] [blame] | 92 | * WARNING: if you add a flag here you need to make sure it's |
| 93 | * accounted for in minijail_pre{enter|exec}() below. |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 94 | */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 95 | struct { |
Luis Hector Chavez | fb449ab | 2016-10-14 09:49:22 -0700 | [diff] [blame] | 96 | int uid : 1; |
| 97 | int gid : 1; |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 98 | int inherit_suppl_gids : 1; |
| 99 | int set_suppl_gids : 1; |
| 100 | int keep_suppl_gids : 1; |
Luis Hector Chavez | fb449ab | 2016-10-14 09:49:22 -0700 | [diff] [blame] | 101 | int use_caps : 1; |
| 102 | int capbset_drop : 1; |
Jorge Lucangeli Obes | a6eb21a | 2017-04-20 10:44:00 -0400 | [diff] [blame] | 103 | int set_ambient_caps : 1; |
Luis Hector Chavez | fb449ab | 2016-10-14 09:49:22 -0700 | [diff] [blame] | 104 | int vfs : 1; |
| 105 | int enter_vfs : 1; |
| 106 | int skip_remount_private : 1; |
| 107 | int pids : 1; |
| 108 | int ipc : 1; |
| 109 | int net : 1; |
| 110 | int enter_net : 1; |
| 111 | int ns_cgroups : 1; |
| 112 | int userns : 1; |
| 113 | int disable_setgroups : 1; |
| 114 | int seccomp : 1; |
| 115 | int remount_proc_ro : 1; |
| 116 | int no_new_privs : 1; |
| 117 | int seccomp_filter : 1; |
| 118 | int seccomp_filter_tsync : 1; |
| 119 | int seccomp_filter_logging : 1; |
| 120 | int chroot : 1; |
| 121 | int pivot_root : 1; |
| 122 | int mount_tmp : 1; |
| 123 | int do_init : 1; |
| 124 | int pid_file : 1; |
| 125 | int cgroups : 1; |
| 126 | int alt_syscall : 1; |
| 127 | int reset_signal_mask : 1; |
| 128 | int close_open_fds : 1; |
Chirantan Ekbote | 866bb3a | 2017-02-07 12:26:42 -0800 | [diff] [blame] | 129 | int new_session_keyring : 1; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 130 | } flags; |
| 131 | uid_t uid; |
| 132 | gid_t gid; |
| 133 | gid_t usergid; |
| 134 | char *user; |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 135 | size_t suppl_gid_count; |
| 136 | gid_t *suppl_gid_list; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 137 | uint64_t caps; |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 138 | uint64_t cap_bset; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 139 | pid_t initpid; |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 140 | int mountns_fd; |
Dylan Reid | 1102f5a | 2015-09-15 11:52:20 -0700 | [diff] [blame] | 141 | int netns_fd; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 142 | char *chrootdir; |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 143 | char *pid_file_path; |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 144 | char *uidmap; |
| 145 | char *gidmap; |
Jorge Lucangeli Obes | c2ba9f5 | 2015-12-01 07:58:10 -0800 | [diff] [blame] | 146 | size_t filter_len; |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 147 | struct sock_fprog *filter_prog; |
Jorge Lucangeli Obes | c2ba9f5 | 2015-12-01 07:58:10 -0800 | [diff] [blame] | 148 | char *alt_syscall_table; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 149 | struct mountpoint *mounts_head; |
| 150 | struct mountpoint *mounts_tail; |
Jorge Lucangeli Obes | c2ba9f5 | 2015-12-01 07:58:10 -0800 | [diff] [blame] | 151 | size_t mounts_count; |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 152 | size_t tmpfs_size; |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 153 | char *cgroups[MAX_CGROUPS]; |
| 154 | size_t cgroup_count; |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 155 | }; |
| 156 | |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 157 | /* |
| 158 | * Strip out flags meant for the parent. |
| 159 | * We keep things that are not inherited across execve(2) (e.g. capabilities), |
| 160 | * or are easier to set after execve(2) (e.g. seccomp filters). |
| 161 | */ |
| 162 | void minijail_preenter(struct minijail *j) |
| 163 | { |
| 164 | j->flags.vfs = 0; |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 165 | j->flags.enter_vfs = 0; |
Shuhei Takahashi | 3da4031 | 2016-03-07 17:37:49 +0900 | [diff] [blame] | 166 | j->flags.skip_remount_private = 0; |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 167 | j->flags.remount_proc_ro = 0; |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 168 | j->flags.pids = 0; |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 169 | j->flags.do_init = 0; |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 170 | j->flags.pid_file = 0; |
Jorge Lucangeli Obes | b8a5138 | 2016-01-25 20:08:22 -0800 | [diff] [blame] | 171 | j->flags.cgroups = 0; |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Strip out flags meant for the child. |
| 176 | * We keep things that are inherited across execve(2). |
| 177 | */ |
| 178 | void minijail_preexec(struct minijail *j) |
| 179 | { |
| 180 | int vfs = j->flags.vfs; |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 181 | int enter_vfs = j->flags.enter_vfs; |
Jorge Lucangeli Obes | 87bf01d | 2016-03-08 11:20:03 -0800 | [diff] [blame] | 182 | int skip_remount_private = j->flags.skip_remount_private; |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 183 | int remount_proc_ro = j->flags.remount_proc_ro; |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 184 | int userns = j->flags.userns; |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 185 | if (j->user) |
| 186 | free(j->user); |
| 187 | j->user = NULL; |
Jorge Lucangeli Obes | e81a52f | 2015-12-04 16:05:23 -0800 | [diff] [blame] | 188 | if (j->suppl_gid_list) |
| 189 | free(j->suppl_gid_list); |
| 190 | j->suppl_gid_list = NULL; |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 191 | memset(&j->flags, 0, sizeof(j->flags)); |
| 192 | /* Now restore anything we meant to keep. */ |
| 193 | j->flags.vfs = vfs; |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 194 | j->flags.enter_vfs = enter_vfs; |
Jorge Lucangeli Obes | 87bf01d | 2016-03-08 11:20:03 -0800 | [diff] [blame] | 195 | j->flags.skip_remount_private = skip_remount_private; |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 196 | j->flags.remount_proc_ro = remount_proc_ro; |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 197 | j->flags.userns = userns; |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 198 | /* Note, |pids| will already have been used before this call. */ |
| 199 | } |
| 200 | |
| 201 | /* Minijail API. */ |
| 202 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 203 | struct minijail API *minijail_new(void) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 204 | { |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 205 | return calloc(1, sizeof(struct minijail)); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 206 | } |
| 207 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 208 | void API minijail_change_uid(struct minijail *j, uid_t uid) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 209 | { |
| 210 | if (uid == 0) |
| 211 | die("useless change to uid 0"); |
| 212 | j->uid = uid; |
| 213 | j->flags.uid = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 214 | } |
| 215 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 216 | void API minijail_change_gid(struct minijail *j, gid_t gid) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 217 | { |
| 218 | if (gid == 0) |
| 219 | die("useless change to gid 0"); |
| 220 | j->gid = gid; |
| 221 | j->flags.gid = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 222 | } |
| 223 | |
Jorge Lucangeli Obes | bc67f44 | 2016-01-08 14:43:45 -0800 | [diff] [blame] | 224 | void API minijail_set_supplementary_gids(struct minijail *j, size_t size, |
| 225 | const gid_t *list) |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 226 | { |
Jorge Lucangeli Obes | 06940be | 2015-12-04 18:09:21 -0800 | [diff] [blame] | 227 | size_t i; |
| 228 | |
Jorge Lucangeli Obes | 3454319 | 2017-01-11 16:07:57 -0500 | [diff] [blame] | 229 | if (j->flags.inherit_suppl_gids) |
| 230 | die("cannot inherit *and* set supplementary groups"); |
| 231 | if (j->flags.keep_suppl_gids) |
| 232 | die("cannot keep *and* set supplementary groups"); |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 233 | |
Jorge Lucangeli Obes | fd5fc56 | 2016-01-08 10:29:27 -0800 | [diff] [blame] | 234 | if (size == 0) { |
| 235 | /* Clear supplementary groups. */ |
| 236 | j->suppl_gid_list = NULL; |
| 237 | j->suppl_gid_count = 0; |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 238 | j->flags.set_suppl_gids = 1; |
Jorge Lucangeli Obes | bc67f44 | 2016-01-08 14:43:45 -0800 | [diff] [blame] | 239 | return; |
Jorge Lucangeli Obes | fd5fc56 | 2016-01-08 10:29:27 -0800 | [diff] [blame] | 240 | } |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 241 | |
| 242 | /* Copy the gid_t array. */ |
| 243 | j->suppl_gid_list = calloc(size, sizeof(gid_t)); |
| 244 | if (!j->suppl_gid_list) { |
Jorge Lucangeli Obes | fd5fc56 | 2016-01-08 10:29:27 -0800 | [diff] [blame] | 245 | die("failed to allocate internal supplementary group array"); |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 246 | } |
Jorge Lucangeli Obes | 06940be | 2015-12-04 18:09:21 -0800 | [diff] [blame] | 247 | for (i = 0; i < size; i++) { |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 248 | j->suppl_gid_list[i] = list[i]; |
| 249 | } |
| 250 | j->suppl_gid_count = size; |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 251 | j->flags.set_suppl_gids = 1; |
| 252 | } |
| 253 | |
| 254 | void API minijail_keep_supplementary_gids(struct minijail *j) { |
| 255 | j->flags.keep_suppl_gids = 1; |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 256 | } |
| 257 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 258 | int API minijail_change_user(struct minijail *j, const char *user) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 259 | { |
| 260 | char *buf = NULL; |
| 261 | struct passwd pw; |
| 262 | struct passwd *ppw = NULL; |
| 263 | ssize_t sz = sysconf(_SC_GETPW_R_SIZE_MAX); |
| 264 | if (sz == -1) |
| 265 | sz = 65536; /* your guess is as good as mine... */ |
Elly Jones | eb300c5 | 2011-09-22 14:35:43 -0400 | [diff] [blame] | 266 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 267 | /* |
| 268 | * sysconf(_SC_GETPW_R_SIZE_MAX), under glibc, is documented to return |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 269 | * the maximum needed size of the buffer, so we don't have to search. |
| 270 | */ |
| 271 | buf = malloc(sz); |
| 272 | if (!buf) |
| 273 | return -ENOMEM; |
| 274 | getpwnam_r(user, &pw, buf, sz, &ppw); |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 275 | /* |
Jorge Lucangeli Obes | b8a5138 | 2016-01-25 20:08:22 -0800 | [diff] [blame] | 276 | * We're safe to free the buffer here. The strings inside |pw| point |
| 277 | * inside |buf|, but we don't use any of them; this leaves the pointers |
Jorge Lucangeli Obes | 87bf01d | 2016-03-08 11:20:03 -0800 | [diff] [blame] | 278 | * dangling but it's safe. |ppw| points at |pw| if getpwnam_r(3) |
| 279 | * succeeded. |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 280 | */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 281 | free(buf); |
Jorge Lucangeli Obes | 4e48065 | 2014-03-26 10:56:42 -0700 | [diff] [blame] | 282 | /* getpwnam_r(3) does *not* set errno when |ppw| is NULL. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 283 | if (!ppw) |
Jorge Lucangeli Obes | 4e48065 | 2014-03-26 10:56:42 -0700 | [diff] [blame] | 284 | return -1; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 285 | minijail_change_uid(j, ppw->pw_uid); |
| 286 | j->user = strdup(user); |
| 287 | if (!j->user) |
| 288 | return -ENOMEM; |
| 289 | j->usergid = ppw->pw_gid; |
| 290 | return 0; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 291 | } |
| 292 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 293 | int API minijail_change_group(struct minijail *j, const char *group) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 294 | { |
Jorge Lucangeli Obes | a21c8fc | 2015-07-15 16:22:34 -0700 | [diff] [blame] | 295 | char *buf = NULL; |
Yabin Cui | 1b21c8f | 2015-07-22 10:34:45 -0700 | [diff] [blame] | 296 | struct group gr; |
| 297 | struct group *pgr = NULL; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 298 | ssize_t sz = sysconf(_SC_GETGR_R_SIZE_MAX); |
| 299 | if (sz == -1) |
| 300 | sz = 65536; /* and mine is as good as yours, really */ |
Elly Jones | eb300c5 | 2011-09-22 14:35:43 -0400 | [diff] [blame] | 301 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 302 | /* |
| 303 | * sysconf(_SC_GETGR_R_SIZE_MAX), under glibc, is documented to return |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 304 | * the maximum needed size of the buffer, so we don't have to search. |
| 305 | */ |
| 306 | buf = malloc(sz); |
| 307 | if (!buf) |
| 308 | return -ENOMEM; |
| 309 | getgrnam_r(group, &gr, buf, sz, &pgr); |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 310 | /* |
| 311 | * We're safe to free the buffer here. The strings inside gr point |
| 312 | * inside buf, but we don't use any of them; this leaves the pointers |
| 313 | * dangling but it's safe. pgr points at gr if getgrnam_r succeeded. |
| 314 | */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 315 | free(buf); |
Jorge Lucangeli Obes | 4e48065 | 2014-03-26 10:56:42 -0700 | [diff] [blame] | 316 | /* getgrnam_r(3) does *not* set errno when |pgr| is NULL. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 317 | if (!pgr) |
Jorge Lucangeli Obes | 4e48065 | 2014-03-26 10:56:42 -0700 | [diff] [blame] | 318 | return -1; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 319 | minijail_change_gid(j, pgr->gr_gid); |
| 320 | return 0; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 321 | } |
| 322 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 323 | void API minijail_use_seccomp(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 324 | { |
| 325 | j->flags.seccomp = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 326 | } |
| 327 | |
Jorge Lucangeli Obes | c2c9bcc | 2012-05-01 09:30:24 -0700 | [diff] [blame] | 328 | void API minijail_no_new_privs(struct minijail *j) |
| 329 | { |
| 330 | j->flags.no_new_privs = 1; |
| 331 | } |
| 332 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 333 | void API minijail_use_seccomp_filter(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 334 | { |
| 335 | j->flags.seccomp_filter = 1; |
Will Drewry | 32ac9f5 | 2011-08-18 21:36:27 -0500 | [diff] [blame] | 336 | } |
| 337 | |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 338 | void API minijail_set_seccomp_filter_tsync(struct minijail *j) |
| 339 | { |
Jorge Lucangeli Obes | 713f6fb | 2016-10-03 13:03:25 -0400 | [diff] [blame] | 340 | if (j->filter_len > 0 && j->filter_prog != NULL) { |
| 341 | die("minijail_set_seccomp_filter_tsync() must be called " |
| 342 | "before minijail_parse_seccomp_filters()"); |
| 343 | } |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 344 | j->flags.seccomp_filter_tsync = 1; |
| 345 | } |
| 346 | |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 347 | void API minijail_log_seccomp_filter_failures(struct minijail *j) |
| 348 | { |
Jorge Lucangeli Obes | 713f6fb | 2016-10-03 13:03:25 -0400 | [diff] [blame] | 349 | if (j->filter_len > 0 && j->filter_prog != NULL) { |
| 350 | die("minijail_log_seccomp_filter_failures() must be called " |
| 351 | "before minijail_parse_seccomp_filters()"); |
| 352 | } |
| 353 | j->flags.seccomp_filter_logging = 1; |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 354 | } |
| 355 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 356 | void API minijail_use_caps(struct minijail *j, uint64_t capmask) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 357 | { |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 358 | /* |
| 359 | * 'minijail_use_caps' configures a runtime-capabilities-only |
| 360 | * environment, including a bounding set matching the thread's runtime |
| 361 | * (permitted|inheritable|effective) sets. |
| 362 | * Therefore, it will override any existing bounding set configurations |
| 363 | * since the latter would allow gaining extra runtime capabilities from |
| 364 | * file capabilities. |
| 365 | */ |
| 366 | if (j->flags.capbset_drop) { |
| 367 | warn("overriding bounding set configuration"); |
| 368 | j->cap_bset = 0; |
| 369 | j->flags.capbset_drop = 0; |
| 370 | } |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 371 | j->caps = capmask; |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 372 | j->flags.use_caps = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 373 | } |
| 374 | |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 375 | void API minijail_capbset_drop(struct minijail *j, uint64_t capmask) |
| 376 | { |
| 377 | if (j->flags.use_caps) { |
| 378 | /* |
| 379 | * 'minijail_use_caps' will have already configured a capability |
| 380 | * bounding set matching the (permitted|inheritable|effective) |
| 381 | * sets. Abort if the user tries to configure a separate |
| 382 | * bounding set. 'minijail_capbset_drop' and 'minijail_use_caps' |
| 383 | * are mutually exclusive. |
| 384 | */ |
| 385 | die("runtime capabilities already configured, can't drop " |
| 386 | "bounding set separately"); |
| 387 | } |
| 388 | j->cap_bset = capmask; |
| 389 | j->flags.capbset_drop = 1; |
| 390 | } |
| 391 | |
Jorge Lucangeli Obes | a6eb21a | 2017-04-20 10:44:00 -0400 | [diff] [blame] | 392 | void API minijail_set_ambient_caps(struct minijail *j) |
| 393 | { |
| 394 | j->flags.set_ambient_caps = 1; |
| 395 | } |
| 396 | |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 397 | void API minijail_reset_signal_mask(struct minijail *j) |
| 398 | { |
Peter Qiu | 2860c46 | 2015-12-16 15:13:06 -0800 | [diff] [blame] | 399 | j->flags.reset_signal_mask = 1; |
| 400 | } |
| 401 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 402 | void API minijail_namespace_vfs(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 403 | { |
| 404 | j->flags.vfs = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 405 | } |
| 406 | |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 407 | void API minijail_namespace_enter_vfs(struct minijail *j, const char *ns_path) |
| 408 | { |
Ricky Zhou | bce609d | 2016-03-02 21:47:56 -0800 | [diff] [blame] | 409 | int ns_fd = open(ns_path, O_RDONLY | O_CLOEXEC); |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 410 | if (ns_fd < 0) { |
| 411 | pdie("failed to open namespace '%s'", ns_path); |
| 412 | } |
| 413 | j->mountns_fd = ns_fd; |
| 414 | j->flags.enter_vfs = 1; |
| 415 | } |
| 416 | |
Chirantan Ekbote | 866bb3a | 2017-02-07 12:26:42 -0800 | [diff] [blame] | 417 | void API minijail_new_session_keyring(struct minijail *j) |
| 418 | { |
| 419 | j->flags.new_session_keyring = 1; |
| 420 | } |
| 421 | |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 422 | void API minijail_skip_remount_private(struct minijail *j) |
| 423 | { |
| 424 | j->flags.skip_remount_private = 1; |
| 425 | } |
| 426 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 427 | void API minijail_namespace_pids(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 428 | { |
Elly Jones | e58176c | 2012-01-23 11:46:17 -0500 | [diff] [blame] | 429 | j->flags.vfs = 1; |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 430 | j->flags.remount_proc_ro = 1; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 431 | j->flags.pids = 1; |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 432 | j->flags.do_init = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 433 | } |
| 434 | |
Dylan Reid | f794247 | 2015-11-18 17:55:26 -0800 | [diff] [blame] | 435 | void API minijail_namespace_ipc(struct minijail *j) |
| 436 | { |
| 437 | j->flags.ipc = 1; |
| 438 | } |
| 439 | |
Elly Fong-Jones | 6c08630 | 2013-03-20 17:15:28 -0400 | [diff] [blame] | 440 | void API minijail_namespace_net(struct minijail *j) |
| 441 | { |
| 442 | j->flags.net = 1; |
| 443 | } |
| 444 | |
Dylan Reid | 1102f5a | 2015-09-15 11:52:20 -0700 | [diff] [blame] | 445 | void API minijail_namespace_enter_net(struct minijail *j, const char *ns_path) |
| 446 | { |
Ricky Zhou | bce609d | 2016-03-02 21:47:56 -0800 | [diff] [blame] | 447 | int ns_fd = open(ns_path, O_RDONLY | O_CLOEXEC); |
Dylan Reid | 1102f5a | 2015-09-15 11:52:20 -0700 | [diff] [blame] | 448 | if (ns_fd < 0) { |
| 449 | pdie("failed to open namespace '%s'", ns_path); |
| 450 | } |
| 451 | j->netns_fd = ns_fd; |
| 452 | j->flags.enter_net = 1; |
| 453 | } |
| 454 | |
Dylan Reid | 4cbc2a5 | 2016-06-17 19:06:07 -0700 | [diff] [blame] | 455 | void API minijail_namespace_cgroups(struct minijail *j) |
| 456 | { |
| 457 | j->flags.ns_cgroups = 1; |
| 458 | } |
| 459 | |
Luis Hector Chavez | 43ff080 | 2016-10-07 12:21:07 -0700 | [diff] [blame] | 460 | void API minijail_close_open_fds(struct minijail *j) |
| 461 | { |
| 462 | j->flags.close_open_fds = 1; |
| 463 | } |
| 464 | |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 465 | void API minijail_remount_proc_readonly(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 466 | { |
| 467 | j->flags.vfs = 1; |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 468 | j->flags.remount_proc_ro = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 469 | } |
| 470 | |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 471 | void API minijail_namespace_user(struct minijail *j) |
| 472 | { |
| 473 | j->flags.userns = 1; |
| 474 | } |
| 475 | |
Jorge Lucangeli Obes | 200299c | 2016-09-23 15:21:57 -0400 | [diff] [blame] | 476 | void API minijail_namespace_user_disable_setgroups(struct minijail *j) |
| 477 | { |
| 478 | j->flags.disable_setgroups = 1; |
| 479 | } |
| 480 | |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 481 | int API minijail_uidmap(struct minijail *j, const char *uidmap) |
| 482 | { |
| 483 | j->uidmap = strdup(uidmap); |
| 484 | if (!j->uidmap) |
| 485 | return -ENOMEM; |
Yu-Hsi Chiang | 1912c5b | 2015-08-31 18:59:49 +0800 | [diff] [blame] | 486 | char *ch; |
| 487 | for (ch = j->uidmap; *ch; ch++) { |
| 488 | if (*ch == ',') |
| 489 | *ch = '\n'; |
| 490 | } |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 491 | return 0; |
| 492 | } |
| 493 | |
| 494 | int API minijail_gidmap(struct minijail *j, const char *gidmap) |
| 495 | { |
| 496 | j->gidmap = strdup(gidmap); |
| 497 | if (!j->gidmap) |
| 498 | return -ENOMEM; |
Yu-Hsi Chiang | 1912c5b | 2015-08-31 18:59:49 +0800 | [diff] [blame] | 499 | char *ch; |
| 500 | for (ch = j->gidmap; *ch; ch++) { |
| 501 | if (*ch == ',') |
| 502 | *ch = '\n'; |
| 503 | } |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 504 | return 0; |
| 505 | } |
| 506 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 507 | void API minijail_inherit_usergroups(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 508 | { |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 509 | j->flags.inherit_suppl_gids = 1; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 510 | } |
| 511 | |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 512 | void API minijail_run_as_init(struct minijail *j) |
| 513 | { |
| 514 | /* |
| 515 | * Since the jailed program will become 'init' in the new PID namespace, |
| 516 | * Minijail does not need to fork an 'init' process. |
| 517 | */ |
| 518 | j->flags.do_init = 0; |
| 519 | } |
| 520 | |
Jorge Lucangeli Obes | c8b21e1 | 2014-06-13 14:26:16 -0700 | [diff] [blame] | 521 | int API minijail_enter_chroot(struct minijail *j, const char *dir) |
| 522 | { |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 523 | if (j->chrootdir) |
| 524 | return -EINVAL; |
| 525 | j->chrootdir = strdup(dir); |
| 526 | if (!j->chrootdir) |
| 527 | return -ENOMEM; |
| 528 | j->flags.chroot = 1; |
| 529 | return 0; |
| 530 | } |
| 531 | |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 532 | int API minijail_enter_pivot_root(struct minijail *j, const char *dir) |
| 533 | { |
| 534 | if (j->chrootdir) |
| 535 | return -EINVAL; |
| 536 | j->chrootdir = strdup(dir); |
| 537 | if (!j->chrootdir) |
| 538 | return -ENOMEM; |
| 539 | j->flags.pivot_root = 1; |
| 540 | return 0; |
| 541 | } |
| 542 | |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 543 | char API *minijail_get_original_path(struct minijail *j, |
| 544 | const char *path_inside_chroot) |
| 545 | { |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 546 | struct mountpoint *b; |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 547 | |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 548 | b = j->mounts_head; |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 549 | while (b) { |
| 550 | /* |
| 551 | * If |path_inside_chroot| is the exact destination of a |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 552 | * mount, then the original path is exactly the source of |
| 553 | * the mount. |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 554 | * for example: "-b /some/path/exe,/chroot/path/exe" |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 555 | * mount source = /some/path/exe, mount dest = |
| 556 | * /chroot/path/exe Then when getting the original path of |
| 557 | * "/chroot/path/exe", the source of that mount, |
| 558 | * "/some/path/exe" is what should be returned. |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 559 | */ |
| 560 | if (!strcmp(b->dest, path_inside_chroot)) |
| 561 | return strdup(b->src); |
| 562 | |
| 563 | /* |
| 564 | * If |path_inside_chroot| is within the destination path of a |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 565 | * mount, take the suffix of the chroot path relative to the |
| 566 | * mount destination path, and append it to the mount source |
| 567 | * path. |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 568 | */ |
| 569 | if (!strncmp(b->dest, path_inside_chroot, strlen(b->dest))) { |
| 570 | const char *relative_path = |
| 571 | path_inside_chroot + strlen(b->dest); |
Jorge Lucangeli Obes | 7b2e29c | 2016-08-04 12:21:03 -0400 | [diff] [blame] | 572 | return path_join(b->src, relative_path); |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 573 | } |
| 574 | b = b->next; |
| 575 | } |
| 576 | |
| 577 | /* If there is a chroot path, append |path_inside_chroot| to that. */ |
| 578 | if (j->chrootdir) |
Jorge Lucangeli Obes | 7b2e29c | 2016-08-04 12:21:03 -0400 | [diff] [blame] | 579 | return path_join(j->chrootdir, path_inside_chroot); |
Dylan Reid | a14e08d | 2015-10-22 21:05:29 -0700 | [diff] [blame] | 580 | |
| 581 | /* No chroot, so the path outside is the same as it is inside. */ |
| 582 | return strdup(path_inside_chroot); |
Dylan Reid | 08946cc | 2015-09-16 19:10:57 -0700 | [diff] [blame] | 583 | } |
| 584 | |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 585 | size_t minijail_get_tmpfs_size(const struct minijail *j) |
| 586 | { |
| 587 | return j->tmpfs_size; |
| 588 | } |
| 589 | |
Lee Campbell | 11af062 | 2014-05-22 12:36:04 -0700 | [diff] [blame] | 590 | void API minijail_mount_tmp(struct minijail *j) |
| 591 | { |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 592 | minijail_mount_tmp_size(j, 64 * 1024 * 1024); |
| 593 | } |
| 594 | |
| 595 | void API minijail_mount_tmp_size(struct minijail *j, size_t size) |
| 596 | { |
| 597 | j->tmpfs_size = size; |
Lee Campbell | 11af062 | 2014-05-22 12:36:04 -0700 | [diff] [blame] | 598 | j->flags.mount_tmp = 1; |
| 599 | } |
| 600 | |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 601 | int API minijail_write_pid_file(struct minijail *j, const char *path) |
| 602 | { |
| 603 | j->pid_file_path = strdup(path); |
| 604 | if (!j->pid_file_path) |
| 605 | return -ENOMEM; |
| 606 | j->flags.pid_file = 1; |
| 607 | return 0; |
| 608 | } |
| 609 | |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 610 | int API minijail_add_to_cgroup(struct minijail *j, const char *path) |
| 611 | { |
| 612 | if (j->cgroup_count >= MAX_CGROUPS) |
| 613 | return -ENOMEM; |
| 614 | j->cgroups[j->cgroup_count] = strdup(path); |
| 615 | if (!j->cgroups[j->cgroup_count]) |
| 616 | return -ENOMEM; |
| 617 | j->cgroup_count++; |
Jorge Lucangeli Obes | b8a5138 | 2016-01-25 20:08:22 -0800 | [diff] [blame] | 618 | j->flags.cgroups = 1; |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 619 | return 0; |
| 620 | } |
| 621 | |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 622 | int API minijail_mount_with_data(struct minijail *j, const char *src, |
| 623 | const char *dest, const char *type, |
| 624 | unsigned long flags, const char *data) |
Jorge Lucangeli Obes | c8b21e1 | 2014-06-13 14:26:16 -0700 | [diff] [blame] | 625 | { |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 626 | struct mountpoint *m; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 627 | |
| 628 | if (*dest != '/') |
| 629 | return -EINVAL; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 630 | m = calloc(1, sizeof(*m)); |
| 631 | if (!m) |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 632 | return -ENOMEM; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 633 | m->dest = strdup(dest); |
| 634 | if (!m->dest) |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 635 | goto error; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 636 | m->src = strdup(src); |
| 637 | if (!m->src) |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 638 | goto error; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 639 | m->type = strdup(type); |
| 640 | if (!m->type) |
| 641 | goto error; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 642 | if (data) { |
| 643 | m->data = strdup(data); |
| 644 | if (!m->data) |
| 645 | goto error; |
| 646 | m->has_data = 1; |
| 647 | } |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 648 | m->flags = flags; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 649 | |
Jorge Lucangeli Obes | 6c755d2 | 2016-01-28 15:24:40 -0800 | [diff] [blame] | 650 | info("mount %s -> %s type '%s'", src, dest, type); |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 651 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 652 | /* |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 653 | * Force vfs namespacing so the mounts don't leak out into the |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 654 | * containing vfs namespace. |
| 655 | */ |
| 656 | minijail_namespace_vfs(j); |
| 657 | |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 658 | if (j->mounts_tail) |
| 659 | j->mounts_tail->next = m; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 660 | else |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 661 | j->mounts_head = m; |
| 662 | j->mounts_tail = m; |
| 663 | j->mounts_count++; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 664 | |
| 665 | return 0; |
| 666 | |
| 667 | error: |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 668 | free(m->type); |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 669 | free(m->src); |
| 670 | free(m->dest); |
| 671 | free(m); |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 672 | return -ENOMEM; |
| 673 | } |
| 674 | |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 675 | int API minijail_mount(struct minijail *j, const char *src, const char *dest, |
| 676 | const char *type, unsigned long flags) |
| 677 | { |
| 678 | return minijail_mount_with_data(j, src, dest, type, flags, NULL); |
| 679 | } |
| 680 | |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 681 | int API minijail_bind(struct minijail *j, const char *src, const char *dest, |
| 682 | int writeable) |
| 683 | { |
| 684 | unsigned long flags = MS_BIND; |
| 685 | |
| 686 | if (!writeable) |
| 687 | flags |= MS_RDONLY; |
| 688 | |
| 689 | return minijail_mount(j, src, dest, "", flags); |
| 690 | } |
| 691 | |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 692 | static void clear_seccomp_options(struct minijail *j) |
| 693 | { |
| 694 | j->flags.seccomp_filter = 0; |
| 695 | j->flags.seccomp_filter_tsync = 0; |
Jorge Lucangeli Obes | 713f6fb | 2016-10-03 13:03:25 -0400 | [diff] [blame] | 696 | j->flags.seccomp_filter_logging = 0; |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 697 | j->filter_len = 0; |
| 698 | j->filter_prog = NULL; |
| 699 | j->flags.no_new_privs = 0; |
| 700 | } |
| 701 | |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 702 | static int seccomp_should_parse_filters(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 703 | { |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 704 | if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL) == -1) { |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 705 | /* |
| 706 | * |errno| will be set to EINVAL when seccomp has not been |
| 707 | * compiled into the kernel. On certain platforms and kernel |
| 708 | * versions this is not a fatal failure. In that case, and only |
| 709 | * in that case, disable seccomp and skip loading the filters. |
| 710 | */ |
Jorge Lucangeli Obes | 7b2e29c | 2016-08-04 12:21:03 -0400 | [diff] [blame] | 711 | if ((errno == EINVAL) && seccomp_can_softfail()) { |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 712 | warn("not loading seccomp filters, seccomp filter not " |
| 713 | "supported"); |
| 714 | clear_seccomp_options(j); |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 715 | return 0; |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 716 | } |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 717 | /* |
| 718 | * If |errno| != EINVAL or seccomp_can_softfail() is false, |
| 719 | * we can proceed. Worst case scenario minijail_enter() will |
| 720 | * abort() if seccomp fails. |
| 721 | */ |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 722 | } |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 723 | if (j->flags.seccomp_filter_tsync) { |
| 724 | /* Are the seccomp(2) syscall and the TSYNC option supported? */ |
| 725 | if (sys_seccomp(SECCOMP_SET_MODE_FILTER, |
| 726 | SECCOMP_FILTER_FLAG_TSYNC, NULL) == -1) { |
| 727 | int saved_errno = errno; |
Jorge Lucangeli Obes | 713f6fb | 2016-10-03 13:03:25 -0400 | [diff] [blame] | 728 | if (saved_errno == ENOSYS && seccomp_can_softfail()) { |
| 729 | warn("seccomp(2) syscall not supported"); |
| 730 | clear_seccomp_options(j); |
| 731 | return 0; |
| 732 | } else if (saved_errno == EINVAL && |
| 733 | seccomp_can_softfail()) { |
| 734 | warn( |
| 735 | "seccomp filter thread sync not supported"); |
| 736 | clear_seccomp_options(j); |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 737 | return 0; |
| 738 | } |
| 739 | /* |
| 740 | * Similar logic here. If seccomp_can_softfail() is |
| 741 | * false, or |errno| != ENOSYS, or |errno| != EINVAL, |
| 742 | * we can proceed. Worst case scenario minijail_enter() |
| 743 | * will abort() if seccomp or TSYNC fail. |
| 744 | */ |
| 745 | } |
| 746 | } |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 747 | return 1; |
| 748 | } |
| 749 | |
| 750 | static int parse_seccomp_filters(struct minijail *j, FILE *policy_file) |
| 751 | { |
| 752 | struct sock_fprog *fprog = malloc(sizeof(struct sock_fprog)); |
Jorge Lucangeli Obes | 713f6fb | 2016-10-03 13:03:25 -0400 | [diff] [blame] | 753 | int use_ret_trap = |
| 754 | j->flags.seccomp_filter_tsync || j->flags.seccomp_filter_logging; |
| 755 | int allow_logging = j->flags.seccomp_filter_logging; |
| 756 | |
| 757 | if (compile_filter(policy_file, fprog, use_ret_trap, allow_logging)) { |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 758 | free(fprog); |
| 759 | return -1; |
| 760 | } |
| 761 | |
| 762 | j->filter_len = fprog->len; |
| 763 | j->filter_prog = fprog; |
| 764 | return 0; |
| 765 | } |
| 766 | |
| 767 | void API minijail_parse_seccomp_filters(struct minijail *j, const char *path) |
| 768 | { |
| 769 | if (!seccomp_should_parse_filters(j)) |
| 770 | return; |
| 771 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 772 | FILE *file = fopen(path, "r"); |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 773 | if (!file) { |
Jorge Lucangeli Obes | 224e427 | 2012-08-02 14:31:39 -0700 | [diff] [blame] | 774 | pdie("failed to open seccomp filter file '%s'", path); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 775 | } |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 776 | |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 777 | if (parse_seccomp_filters(j, file) != 0) { |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 778 | die("failed to compile seccomp filter BPF program in '%s'", |
| 779 | path); |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 780 | } |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 781 | fclose(file); |
| 782 | } |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 783 | |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 784 | void API minijail_parse_seccomp_filters_from_fd(struct minijail *j, int fd) |
| 785 | { |
| 786 | if (!seccomp_should_parse_filters(j)) |
| 787 | return; |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 788 | |
Jorge Lucangeli Obes | 4d4b3be | 2016-08-16 16:58:14 -0400 | [diff] [blame] | 789 | FILE *file = fdopen(fd, "r"); |
| 790 | if (!file) { |
| 791 | pdie("failed to associate stream with fd %d", fd); |
| 792 | } |
| 793 | |
| 794 | if (parse_seccomp_filters(j, file) != 0) { |
| 795 | die("failed to compile seccomp filter BPF program from fd %d", |
| 796 | fd); |
| 797 | } |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 798 | fclose(file); |
Will Drewry | 32ac9f5 | 2011-08-18 21:36:27 -0500 | [diff] [blame] | 799 | } |
| 800 | |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 801 | int API minijail_use_alt_syscall(struct minijail *j, const char *table) |
| 802 | { |
| 803 | j->alt_syscall_table = strdup(table); |
| 804 | if (!j->alt_syscall_table) |
| 805 | return -ENOMEM; |
| 806 | j->flags.alt_syscall = 1; |
| 807 | return 0; |
| 808 | } |
| 809 | |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 810 | struct marshal_state { |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 811 | size_t available; |
| 812 | size_t total; |
| 813 | char *buf; |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 814 | }; |
| 815 | |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 816 | void marshal_state_init(struct marshal_state *state, char *buf, |
| 817 | size_t available) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 818 | { |
| 819 | state->available = available; |
| 820 | state->buf = buf; |
| 821 | state->total = 0; |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 822 | } |
| 823 | |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 824 | void marshal_append(struct marshal_state *state, void *src, size_t length) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 825 | { |
| 826 | size_t copy_len = MIN(state->available, length); |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 827 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 828 | /* Up to |available| will be written. */ |
| 829 | if (copy_len) { |
| 830 | memcpy(state->buf, src, copy_len); |
| 831 | state->buf += copy_len; |
| 832 | state->available -= copy_len; |
| 833 | } |
| 834 | /* |total| will contain the expected length. */ |
| 835 | state->total += length; |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 836 | } |
| 837 | |
Jorge Lucangeli Obes | 7b2e29c | 2016-08-04 12:21:03 -0400 | [diff] [blame] | 838 | void marshal_mount(struct marshal_state *state, const struct mountpoint *m) |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 839 | { |
| 840 | marshal_append(state, m->src, strlen(m->src) + 1); |
| 841 | marshal_append(state, m->dest, strlen(m->dest) + 1); |
| 842 | marshal_append(state, m->type, strlen(m->type) + 1); |
| 843 | marshal_append(state, (char *)&m->has_data, sizeof(m->has_data)); |
| 844 | if (m->has_data) |
| 845 | marshal_append(state, m->data, strlen(m->data) + 1); |
| 846 | marshal_append(state, (char *)&m->flags, sizeof(m->flags)); |
| 847 | } |
| 848 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 849 | void minijail_marshal_helper(struct marshal_state *state, |
| 850 | const struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 851 | { |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 852 | struct mountpoint *m = NULL; |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 853 | size_t i; |
| 854 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 855 | marshal_append(state, (char *)j, sizeof(*j)); |
| 856 | if (j->user) |
| 857 | marshal_append(state, j->user, strlen(j->user) + 1); |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 858 | if (j->suppl_gid_list) { |
| 859 | marshal_append(state, j->suppl_gid_list, |
| 860 | j->suppl_gid_count * sizeof(gid_t)); |
| 861 | } |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 862 | if (j->chrootdir) |
| 863 | marshal_append(state, j->chrootdir, strlen(j->chrootdir) + 1); |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 864 | if (j->alt_syscall_table) { |
| 865 | marshal_append(state, j->alt_syscall_table, |
| 866 | strlen(j->alt_syscall_table) + 1); |
| 867 | } |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 868 | if (j->flags.seccomp_filter && j->filter_prog) { |
| 869 | struct sock_fprog *fp = j->filter_prog; |
| 870 | marshal_append(state, (char *)fp->filter, |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 871 | fp->len * sizeof(struct sock_filter)); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 872 | } |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 873 | for (m = j->mounts_head; m; m = m->next) { |
Jorge Lucangeli Obes | 7b2e29c | 2016-08-04 12:21:03 -0400 | [diff] [blame] | 874 | marshal_mount(state, m); |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 875 | } |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 876 | for (i = 0; i < j->cgroup_count; ++i) |
| 877 | marshal_append(state, j->cgroups[i], strlen(j->cgroups[i]) + 1); |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 878 | } |
| 879 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 880 | size_t API minijail_size(const struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 881 | { |
| 882 | struct marshal_state state; |
| 883 | marshal_state_init(&state, NULL, 0); |
| 884 | minijail_marshal_helper(&state, j); |
| 885 | return state.total; |
Will Drewry | 2ddaad0 | 2011-09-16 11:36:08 -0500 | [diff] [blame] | 886 | } |
| 887 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 888 | int minijail_marshal(const struct minijail *j, char *buf, size_t available) |
| 889 | { |
| 890 | struct marshal_state state; |
| 891 | marshal_state_init(&state, buf, available); |
| 892 | minijail_marshal_helper(&state, j); |
| 893 | return (state.total > available); |
Will Drewry | 2ddaad0 | 2011-09-16 11:36:08 -0500 | [diff] [blame] | 894 | } |
| 895 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 896 | int minijail_unmarshal(struct minijail *j, char *serialized, size_t length) |
| 897 | { |
Jorge Lucangeli Obes | c2ba9f5 | 2015-12-01 07:58:10 -0800 | [diff] [blame] | 898 | size_t i; |
| 899 | size_t count; |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 900 | int ret = -EINVAL; |
| 901 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 902 | if (length < sizeof(*j)) |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 903 | goto out; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 904 | memcpy((void *)j, serialized, sizeof(*j)); |
| 905 | serialized += sizeof(*j); |
| 906 | length -= sizeof(*j); |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 907 | |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 908 | /* Potentially stale pointers not used as signals. */ |
Jorge Lucangeli Obes | 3b2e6e4 | 2016-08-04 12:26:19 -0400 | [diff] [blame] | 909 | j->pid_file_path = NULL; |
| 910 | j->uidmap = NULL; |
| 911 | j->gidmap = NULL; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 912 | j->mounts_head = NULL; |
| 913 | j->mounts_tail = NULL; |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 914 | j->filter_prog = NULL; |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 915 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 916 | if (j->user) { /* stale pointer */ |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 917 | char *user = consumestr(&serialized, &length); |
| 918 | if (!user) |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 919 | goto clear_pointers; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 920 | j->user = strdup(user); |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 921 | if (!j->user) |
| 922 | goto clear_pointers; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 923 | } |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 924 | |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 925 | if (j->suppl_gid_list) { /* stale pointer */ |
| 926 | if (j->suppl_gid_count > NGROUPS_MAX) { |
| 927 | goto bad_gid_list; |
| 928 | } |
| 929 | size_t gid_list_size = j->suppl_gid_count * sizeof(gid_t); |
| 930 | void *gid_list_bytes = |
| 931 | consumebytes(gid_list_size, &serialized, &length); |
| 932 | if (!gid_list_bytes) |
| 933 | goto bad_gid_list; |
| 934 | |
| 935 | j->suppl_gid_list = calloc(j->suppl_gid_count, sizeof(gid_t)); |
| 936 | if (!j->suppl_gid_list) |
| 937 | goto bad_gid_list; |
| 938 | |
| 939 | memcpy(j->suppl_gid_list, gid_list_bytes, gid_list_size); |
| 940 | } |
| 941 | |
Elly Jones | a8d1e1b | 2011-10-21 15:38:00 -0400 | [diff] [blame] | 942 | if (j->chrootdir) { /* stale pointer */ |
| 943 | char *chrootdir = consumestr(&serialized, &length); |
| 944 | if (!chrootdir) |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 945 | goto bad_chrootdir; |
Elly Jones | a8d1e1b | 2011-10-21 15:38:00 -0400 | [diff] [blame] | 946 | j->chrootdir = strdup(chrootdir); |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 947 | if (!j->chrootdir) |
| 948 | goto bad_chrootdir; |
Elly Jones | a8d1e1b | 2011-10-21 15:38:00 -0400 | [diff] [blame] | 949 | } |
| 950 | |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 951 | if (j->alt_syscall_table) { /* stale pointer */ |
| 952 | char *alt_syscall_table = consumestr(&serialized, &length); |
| 953 | if (!alt_syscall_table) |
| 954 | goto bad_syscall_table; |
| 955 | j->alt_syscall_table = strdup(alt_syscall_table); |
| 956 | if (!j->alt_syscall_table) |
| 957 | goto bad_syscall_table; |
| 958 | } |
| 959 | |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 960 | if (j->flags.seccomp_filter && j->filter_len > 0) { |
| 961 | size_t ninstrs = j->filter_len; |
| 962 | if (ninstrs > (SIZE_MAX / sizeof(struct sock_filter)) || |
| 963 | ninstrs > USHRT_MAX) |
| 964 | goto bad_filters; |
| 965 | |
| 966 | size_t program_len = ninstrs * sizeof(struct sock_filter); |
| 967 | void *program = consumebytes(program_len, &serialized, &length); |
| 968 | if (!program) |
| 969 | goto bad_filters; |
| 970 | |
| 971 | j->filter_prog = malloc(sizeof(struct sock_fprog)); |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 972 | if (!j->filter_prog) |
| 973 | goto bad_filters; |
| 974 | |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 975 | j->filter_prog->len = ninstrs; |
| 976 | j->filter_prog->filter = malloc(program_len); |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 977 | if (!j->filter_prog->filter) |
| 978 | goto bad_filter_prog_instrs; |
| 979 | |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 980 | memcpy(j->filter_prog->filter, program, program_len); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 981 | } |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 982 | |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 983 | count = j->mounts_count; |
| 984 | j->mounts_count = 0; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 985 | for (i = 0; i < count; ++i) { |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 986 | unsigned long *flags; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 987 | int *has_data; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 988 | const char *dest; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 989 | const char *type; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 990 | const char *data = NULL; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 991 | const char *src = consumestr(&serialized, &length); |
| 992 | if (!src) |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 993 | goto bad_mounts; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 994 | dest = consumestr(&serialized, &length); |
| 995 | if (!dest) |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 996 | goto bad_mounts; |
| 997 | type = consumestr(&serialized, &length); |
| 998 | if (!type) |
| 999 | goto bad_mounts; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 1000 | has_data = consumebytes(sizeof(*has_data), &serialized, |
| 1001 | &length); |
| 1002 | if (!has_data) |
| 1003 | goto bad_mounts; |
| 1004 | if (*has_data) { |
| 1005 | data = consumestr(&serialized, &length); |
| 1006 | if (!data) |
| 1007 | goto bad_mounts; |
| 1008 | } |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1009 | flags = consumebytes(sizeof(*flags), &serialized, &length); |
| 1010 | if (!flags) |
| 1011 | goto bad_mounts; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 1012 | if (minijail_mount_with_data(j, src, dest, type, *flags, data)) |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1013 | goto bad_mounts; |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1014 | } |
| 1015 | |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1016 | count = j->cgroup_count; |
| 1017 | j->cgroup_count = 0; |
| 1018 | for (i = 0; i < count; ++i) { |
| 1019 | char *cgroup = consumestr(&serialized, &length); |
| 1020 | if (!cgroup) |
| 1021 | goto bad_cgroups; |
| 1022 | j->cgroups[i] = strdup(cgroup); |
| 1023 | if (!j->cgroups[i]) |
| 1024 | goto bad_cgroups; |
| 1025 | ++j->cgroup_count; |
| 1026 | } |
| 1027 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1028 | return 0; |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 1029 | |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1030 | bad_cgroups: |
| 1031 | while (j->mounts_head) { |
| 1032 | struct mountpoint *m = j->mounts_head; |
| 1033 | j->mounts_head = j->mounts_head->next; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 1034 | free(m->data); |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1035 | free(m->type); |
| 1036 | free(m->dest); |
| 1037 | free(m->src); |
| 1038 | free(m); |
| 1039 | } |
| 1040 | for (i = 0; i < j->cgroup_count; ++i) |
| 1041 | free(j->cgroups[i]); |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1042 | bad_mounts: |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 1043 | if (j->flags.seccomp_filter && j->filter_len > 0) { |
| 1044 | free(j->filter_prog->filter); |
| 1045 | free(j->filter_prog); |
| 1046 | } |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 1047 | bad_filter_prog_instrs: |
| 1048 | if (j->filter_prog) |
| 1049 | free(j->filter_prog); |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 1050 | bad_filters: |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 1051 | if (j->alt_syscall_table) |
| 1052 | free(j->alt_syscall_table); |
| 1053 | bad_syscall_table: |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 1054 | if (j->chrootdir) |
| 1055 | free(j->chrootdir); |
| 1056 | bad_chrootdir: |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 1057 | if (j->suppl_gid_list) |
| 1058 | free(j->suppl_gid_list); |
| 1059 | bad_gid_list: |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 1060 | if (j->user) |
| 1061 | free(j->user); |
| 1062 | clear_pointers: |
| 1063 | j->user = NULL; |
Jorge Lucangeli Obes | de02a5b | 2015-12-11 15:28:52 -0800 | [diff] [blame] | 1064 | j->suppl_gid_list = NULL; |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 1065 | j->chrootdir = NULL; |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 1066 | j->alt_syscall_table = NULL; |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1067 | j->cgroup_count = 0; |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 1068 | out: |
| 1069 | return ret; |
Will Drewry | 2ddaad0 | 2011-09-16 11:36:08 -0500 | [diff] [blame] | 1070 | } |
| 1071 | |
Jorge Lucangeli Obes | d0a6e2f | 2015-11-24 14:21:21 -0800 | [diff] [blame] | 1072 | /* |
| 1073 | * mount_one: Applies mounts from @m for @j, recursing as needed. |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1074 | * @j Minijail these mounts are for |
| 1075 | * @m Head of list of mounts |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1076 | * |
| 1077 | * Returns 0 for success. |
| 1078 | */ |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1079 | static int mount_one(const struct minijail *j, struct mountpoint *m) |
Jorge Lucangeli Obes | c8b21e1 | 2014-06-13 14:26:16 -0700 | [diff] [blame] | 1080 | { |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1081 | int ret; |
| 1082 | char *dest; |
| 1083 | int remount_ro = 0; |
| 1084 | |
Jorge Lucangeli Obes | 2b12ba4 | 2016-01-26 10:37:51 -0800 | [diff] [blame] | 1085 | /* |dest| has a leading "/". */ |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1086 | if (asprintf(&dest, "%s%s", j->chrootdir, m->dest) < 0) |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1087 | return -ENOMEM; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1088 | |
Dylan Reid | eec7796 | 2016-06-30 19:35:10 -0700 | [diff] [blame] | 1089 | if (setup_mount_destination(m->src, dest, j->uid, j->gid)) |
| 1090 | pdie("creating mount target '%s' failed", dest); |
| 1091 | |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1092 | /* |
Jorge Lucangeli Obes | 2b12ba4 | 2016-01-26 10:37:51 -0800 | [diff] [blame] | 1093 | * R/O bind mounts have to be remounted since 'bind' and 'ro' |
| 1094 | * can't both be specified in the original bind mount. |
| 1095 | * Remount R/O after the initial mount. |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1096 | */ |
| 1097 | if ((m->flags & MS_BIND) && (m->flags & MS_RDONLY)) { |
| 1098 | remount_ro = 1; |
| 1099 | m->flags &= ~MS_RDONLY; |
Elly Jones | a105963 | 2011-12-15 15:17:07 -0500 | [diff] [blame] | 1100 | } |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1101 | |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 1102 | ret = mount(m->src, dest, m->type, m->flags, m->data); |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1103 | if (ret) |
| 1104 | pdie("mount: %s -> %s", m->src, dest); |
| 1105 | |
| 1106 | if (remount_ro) { |
| 1107 | m->flags |= MS_RDONLY; |
| 1108 | ret = mount(m->src, dest, NULL, |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 1109 | m->flags | MS_REMOUNT, m->data); |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1110 | if (ret) |
| 1111 | pdie("bind ro: %s -> %s", m->src, dest); |
| 1112 | } |
| 1113 | |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1114 | free(dest); |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1115 | if (m->next) |
| 1116 | return mount_one(j, m->next); |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1117 | return ret; |
| 1118 | } |
| 1119 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1120 | static int enter_chroot(const struct minijail *j) |
Jorge Lucangeli Obes | c8b21e1 | 2014-06-13 14:26:16 -0700 | [diff] [blame] | 1121 | { |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1122 | int ret; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1123 | |
| 1124 | if (j->mounts_head && (ret = mount_one(j, j->mounts_head))) |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1125 | return ret; |
| 1126 | |
| 1127 | if (chroot(j->chrootdir)) |
| 1128 | return -errno; |
| 1129 | |
| 1130 | if (chdir("/")) |
| 1131 | return -errno; |
| 1132 | |
| 1133 | return 0; |
| 1134 | } |
| 1135 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1136 | static int enter_pivot_root(const struct minijail *j) |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1137 | { |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1138 | int ret, oldroot, newroot; |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 1139 | |
| 1140 | if (j->mounts_head && (ret = mount_one(j, j->mounts_head))) |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1141 | return ret; |
| 1142 | |
Jorge Lucangeli Obes | 43a6a86 | 2015-12-04 14:53:36 -0800 | [diff] [blame] | 1143 | /* |
| 1144 | * Keep the fd for both old and new root. |
Jorge Lucangeli Obes | 6b0de9b | 2016-03-16 22:41:34 -0700 | [diff] [blame] | 1145 | * It will be used in fchdir(2) later. |
Jorge Lucangeli Obes | 43a6a86 | 2015-12-04 14:53:36 -0800 | [diff] [blame] | 1146 | */ |
Ricky Zhou | bce609d | 2016-03-02 21:47:56 -0800 | [diff] [blame] | 1147 | oldroot = open("/", O_DIRECTORY | O_RDONLY | O_CLOEXEC); |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1148 | if (oldroot < 0) |
| 1149 | pdie("failed to open / for fchdir"); |
Ricky Zhou | bce609d | 2016-03-02 21:47:56 -0800 | [diff] [blame] | 1150 | newroot = open(j->chrootdir, O_DIRECTORY | O_RDONLY | O_CLOEXEC); |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1151 | if (newroot < 0) |
| 1152 | pdie("failed to open %s for fchdir", j->chrootdir); |
| 1153 | |
Jorge Lucangeli Obes | 43a6a86 | 2015-12-04 14:53:36 -0800 | [diff] [blame] | 1154 | /* |
Jorge Lucangeli Obes | 6b0de9b | 2016-03-16 22:41:34 -0700 | [diff] [blame] | 1155 | * To ensure j->chrootdir is the root of a filesystem, |
Jorge Lucangeli Obes | 43a6a86 | 2015-12-04 14:53:36 -0800 | [diff] [blame] | 1156 | * do a self bind mount. |
| 1157 | */ |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1158 | if (mount(j->chrootdir, j->chrootdir, "bind", MS_BIND | MS_REC, "")) |
| 1159 | pdie("failed to bind mount '%s'", j->chrootdir); |
| 1160 | if (chdir(j->chrootdir)) |
| 1161 | return -errno; |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1162 | if (syscall(SYS_pivot_root, ".", ".")) |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1163 | pdie("pivot_root"); |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1164 | |
| 1165 | /* |
Jorge Lucangeli Obes | 6b0de9b | 2016-03-16 22:41:34 -0700 | [diff] [blame] | 1166 | * Now the old root is mounted on top of the new root. Use fchdir(2) to |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1167 | * change to the old root and unmount it. |
| 1168 | */ |
| 1169 | if (fchdir(oldroot)) |
| 1170 | pdie("failed to fchdir to old /"); |
Hidehiko Abe | 097b719 | 2016-03-16 18:00:36 +0900 | [diff] [blame] | 1171 | |
| 1172 | /* |
Jorge Lucangeli Obes | df7fab1 | 2016-06-01 17:15:31 -0700 | [diff] [blame] | 1173 | * If j->flags.skip_remount_private was enabled for minijail_enter(), |
| 1174 | * there could be a shared mount point under |oldroot|. In that case, |
| 1175 | * mounts under this shared mount point will be unmounted below, and |
| 1176 | * this unmounting will propagate to the original mount namespace |
| 1177 | * (because the mount point is shared). To prevent this unexpected |
| 1178 | * unmounting, remove these mounts from their peer groups by recursively |
| 1179 | * remounting them as MS_PRIVATE. |
Hidehiko Abe | 097b719 | 2016-03-16 18:00:36 +0900 | [diff] [blame] | 1180 | */ |
| 1181 | if (mount(NULL, ".", NULL, MS_REC | MS_PRIVATE, NULL)) |
Jorge Lucangeli Obes | 6b0de9b | 2016-03-16 22:41:34 -0700 | [diff] [blame] | 1182 | pdie("failed to mount(/, private) before umount(/)"); |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1183 | /* The old root might be busy, so use lazy unmount. */ |
Yu-Hsi Chiang | e0a530e | 2015-09-08 18:49:49 +0800 | [diff] [blame] | 1184 | if (umount2(".", MNT_DETACH)) |
| 1185 | pdie("umount(/)"); |
| 1186 | /* Change back to the new root. */ |
| 1187 | if (fchdir(newroot)) |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1188 | return -errno; |
Ricky Zhou | bce609d | 2016-03-02 21:47:56 -0800 | [diff] [blame] | 1189 | if (close(oldroot)) |
| 1190 | return -errno; |
| 1191 | if (close(newroot)) |
| 1192 | return -errno; |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1193 | if (chroot("/")) |
| 1194 | return -errno; |
Jorge Lucangeli Obes | 46a5509 | 2015-10-12 15:31:59 -0700 | [diff] [blame] | 1195 | /* Set correct CWD for getcwd(3). */ |
| 1196 | if (chdir("/")) |
| 1197 | return -errno; |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1198 | |
| 1199 | return 0; |
| 1200 | } |
| 1201 | |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 1202 | static int mount_tmp(const struct minijail *j) |
Lee Campbell | 11af062 | 2014-05-22 12:36:04 -0700 | [diff] [blame] | 1203 | { |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 1204 | const char fmt[] = "size=%zu,mode=1777"; |
| 1205 | /* Count for the user storing ULLONG_MAX literally + extra space. */ |
| 1206 | char data[sizeof(fmt) + sizeof("18446744073709551615ULL")]; |
| 1207 | int ret; |
| 1208 | |
| 1209 | ret = snprintf(data, sizeof(data), fmt, j->tmpfs_size); |
| 1210 | |
| 1211 | if (ret <= 0) |
| 1212 | pdie("tmpfs size spec error"); |
| 1213 | else if ((size_t)ret >= sizeof(data)) |
| 1214 | pdie("tmpfs size spec too large"); |
Mike Frysinger | b91d404 | 2017-01-13 19:03:34 -0500 | [diff] [blame] | 1215 | return mount("none", "/tmp", "tmpfs", MS_NODEV | MS_NOEXEC | MS_NOSUID, |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 1216 | data); |
Lee Campbell | 11af062 | 2014-05-22 12:36:04 -0700 | [diff] [blame] | 1217 | } |
| 1218 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1219 | static int remount_proc_readonly(const struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1220 | { |
| 1221 | const char *kProcPath = "/proc"; |
| 1222 | const unsigned int kSafeFlags = MS_NODEV | MS_NOEXEC | MS_NOSUID; |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1223 | /* |
| 1224 | * Right now, we're holding a reference to our parent's old mount of |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1225 | * /proc in our namespace, which means using MS_REMOUNT here would |
| 1226 | * mutate our parent's mount as well, even though we're in a VFS |
Jorge Lucangeli Obes | df7fab1 | 2016-06-01 17:15:31 -0700 | [diff] [blame] | 1227 | * namespace (!). Instead, remove their mount from our namespace lazily |
| 1228 | * (MNT_DETACH) and make our own. |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1229 | */ |
Jorge Lucangeli Obes | df7fab1 | 2016-06-01 17:15:31 -0700 | [diff] [blame] | 1230 | if (umount2(kProcPath, MNT_DETACH)) { |
| 1231 | /* |
| 1232 | * If we are in a new user namespace, umount(2) will fail. |
| 1233 | * See http://man7.org/linux/man-pages/man7/user_namespaces.7.html |
| 1234 | */ |
| 1235 | if (j->flags.userns) { |
| 1236 | info("umount(/proc, MNT_DETACH) failed, " |
| 1237 | "this is expected when using user namespaces"); |
| 1238 | } else { |
| 1239 | return -errno; |
| 1240 | } |
| 1241 | } |
Mike Frysinger | 3ba8157 | 2017-01-17 23:33:28 -0500 | [diff] [blame] | 1242 | if (mount("proc", kProcPath, "proc", kSafeFlags | MS_RDONLY, "")) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1243 | return -errno; |
| 1244 | return 0; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1245 | } |
| 1246 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1247 | static void kill_child_and_die(const struct minijail *j, const char *msg) |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 1248 | { |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1249 | kill(j->initpid, SIGKILL); |
| 1250 | die("%s", msg); |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1251 | } |
| 1252 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1253 | static void write_pid_file_or_die(const struct minijail *j) |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1254 | { |
Keshav Santhanam | db6dab4 | 2016-08-10 16:33:34 -0700 | [diff] [blame] | 1255 | if (write_pid_to_path(j->initpid, j->pid_file_path)) |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1256 | kill_child_and_die(j, "failed to write pid file"); |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1257 | } |
| 1258 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1259 | static void add_to_cgroups_or_die(const struct minijail *j) |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 1260 | { |
| 1261 | size_t i; |
| 1262 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1263 | for (i = 0; i < j->cgroup_count; ++i) { |
Keshav Santhanam | db6dab4 | 2016-08-10 16:33:34 -0700 | [diff] [blame] | 1264 | if (write_pid_to_path(j->initpid, j->cgroups[i])) |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1265 | kill_child_and_die(j, "failed to add to cgroups"); |
| 1266 | } |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 1267 | } |
| 1268 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1269 | static void write_ugid_maps_or_die(const struct minijail *j) |
| 1270 | { |
| 1271 | if (j->uidmap && write_proc_file(j->initpid, j->uidmap, "uid_map") != 0) |
| 1272 | kill_child_and_die(j, "failed to write uid_map"); |
Mike Frysinger | 6b190c0 | 2017-01-04 17:18:42 -0500 | [diff] [blame] | 1273 | if (j->gidmap && j->flags.disable_setgroups) { |
| 1274 | /* Older kernels might not have the /proc/<pid>/setgroups files. */ |
| 1275 | int ret = write_proc_file(j->initpid, "deny", "setgroups"); |
Mike Frysinger | eea841b | 2017-01-13 18:11:57 -0500 | [diff] [blame] | 1276 | if (ret != 0) { |
Mike Frysinger | 6b190c0 | 2017-01-04 17:18:42 -0500 | [diff] [blame] | 1277 | if (ret == -ENOENT) { |
| 1278 | /* See http://man7.org/linux/man-pages/man7/user_namespaces.7.html. */ |
| 1279 | warn("could not disable setgroups(2)"); |
| 1280 | } else |
| 1281 | kill_child_and_die(j, "failed to disable setgroups(2)"); |
| 1282 | } |
| 1283 | } |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1284 | if (j->gidmap && write_proc_file(j->initpid, j->gidmap, "gid_map") != 0) |
| 1285 | kill_child_and_die(j, "failed to write gid_map"); |
| 1286 | } |
| 1287 | |
| 1288 | static void enter_user_namespace(const struct minijail *j) |
| 1289 | { |
| 1290 | if (j->uidmap && setresuid(0, 0, 0)) |
| 1291 | pdie("user_namespaces: setresuid(0, 0, 0) failed"); |
| 1292 | if (j->gidmap && setresgid(0, 0, 0)) |
| 1293 | pdie("user_namespaces: setresgid(0, 0, 0) failed"); |
| 1294 | } |
| 1295 | |
| 1296 | static void parent_setup_complete(int *pipe_fds) |
| 1297 | { |
| 1298 | close(pipe_fds[0]); |
| 1299 | close(pipe_fds[1]); |
| 1300 | } |
| 1301 | |
| 1302 | /* |
| 1303 | * wait_for_parent_setup: Called by the child process to wait for any |
| 1304 | * further parent-side setup to complete before continuing. |
| 1305 | */ |
| 1306 | static void wait_for_parent_setup(int *pipe_fds) |
| 1307 | { |
| 1308 | char buf; |
| 1309 | |
| 1310 | close(pipe_fds[1]); |
| 1311 | |
| 1312 | /* Wait for parent to complete setup and close the pipe. */ |
| 1313 | if (read(pipe_fds[0], &buf, 1) != 0) |
| 1314 | die("failed to sync with parent"); |
| 1315 | close(pipe_fds[0]); |
| 1316 | } |
| 1317 | |
| 1318 | static void drop_ugid(const struct minijail *j) |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1319 | { |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 1320 | if (j->flags.inherit_suppl_gids + j->flags.keep_suppl_gids + |
| 1321 | j->flags.set_suppl_gids > 1) { |
Jorge Lucangeli Obes | 3454319 | 2017-01-11 16:07:57 -0500 | [diff] [blame] | 1322 | die("can only do one of inherit, keep, or set supplementary " |
| 1323 | "groups"); |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 1324 | } |
| 1325 | |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 1326 | if (j->flags.inherit_suppl_gids) { |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1327 | if (initgroups(j->user, j->usergid)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1328 | pdie("initgroups(%s, %d) failed", j->user, j->usergid); |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 1329 | } else if (j->flags.set_suppl_gids) { |
| 1330 | if (setgroups(j->suppl_gid_count, j->suppl_gid_list)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1331 | pdie("setgroups(suppl_gids) failed"); |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 1332 | } else if (!j->flags.keep_suppl_gids) { |
Jorge Lucangeli Obes | d0a6e2f | 2015-11-24 14:21:21 -0800 | [diff] [blame] | 1333 | /* |
Jorge Lucangeli Obes | d16ac49 | 2015-12-03 14:44:35 -0800 | [diff] [blame] | 1334 | * Only attempt to clear supplementary groups if we are changing |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 1335 | * users or groups. |
Jorge Lucangeli Obes | d0a6e2f | 2015-11-24 14:21:21 -0800 | [diff] [blame] | 1336 | */ |
Jorge Lucangeli Obes | 2449956 | 2016-12-01 11:59:27 -0500 | [diff] [blame] | 1337 | if ((j->flags.uid || j->flags.gid) && setgroups(0, NULL)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1338 | pdie("setgroups(0, NULL) failed"); |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1339 | } |
| 1340 | |
| 1341 | if (j->flags.gid && setresgid(j->gid, j->gid, j->gid)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1342 | pdie("setresgid(%d, %d, %d) failed", j->gid, j->gid, j->gid); |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1343 | |
| 1344 | if (j->flags.uid && setresuid(j->uid, j->uid, j->uid)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1345 | pdie("setresuid(%d, %d, %d) failed", j->uid, j->uid, j->uid); |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1346 | } |
| 1347 | |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 1348 | static void drop_capbset(uint64_t keep_mask, unsigned int last_valid_cap) |
| 1349 | { |
| 1350 | const uint64_t one = 1; |
| 1351 | unsigned int i; |
| 1352 | for (i = 0; i < sizeof(keep_mask) * 8 && i <= last_valid_cap; ++i) { |
| 1353 | if (keep_mask & (one << i)) |
| 1354 | continue; |
| 1355 | if (prctl(PR_CAPBSET_DROP, i)) |
| 1356 | pdie("could not drop capability from bounding set"); |
| 1357 | } |
| 1358 | } |
| 1359 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1360 | static void drop_caps(const struct minijail *j, unsigned int last_valid_cap) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1361 | { |
Jorge Lucangeli Obes | 7ea269e | 2016-02-26 22:07:09 -0800 | [diff] [blame] | 1362 | if (!j->flags.use_caps) |
| 1363 | return; |
| 1364 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1365 | cap_t caps = cap_get_proc(); |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1366 | cap_value_t flag[1]; |
Jorge Lucangeli Obes | a6eb21a | 2017-04-20 10:44:00 -0400 | [diff] [blame] | 1367 | const size_t ncaps = sizeof(j->caps) * 8; |
Kees Cook | e5609ac | 2013-02-06 14:12:41 -0800 | [diff] [blame] | 1368 | const uint64_t one = 1; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1369 | unsigned int i; |
| 1370 | if (!caps) |
| 1371 | die("can't get process caps"); |
Jorge Lucangeli Obes | a6eb21a | 2017-04-20 10:44:00 -0400 | [diff] [blame] | 1372 | if (cap_clear(caps)) |
| 1373 | die("can't clear caps"); |
| 1374 | |
| 1375 | for (i = 0; i < ncaps && i <= last_valid_cap; ++i) { |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1376 | /* Keep CAP_SETPCAP for dropping bounding set bits. */ |
Kees Cook | e5609ac | 2013-02-06 14:12:41 -0800 | [diff] [blame] | 1377 | if (i != CAP_SETPCAP && !(j->caps & (one << i))) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1378 | continue; |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1379 | flag[0] = i; |
| 1380 | if (cap_set_flag(caps, CAP_EFFECTIVE, 1, flag, CAP_SET)) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1381 | die("can't add effective cap"); |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1382 | if (cap_set_flag(caps, CAP_PERMITTED, 1, flag, CAP_SET)) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1383 | die("can't add permitted cap"); |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1384 | if (cap_set_flag(caps, CAP_INHERITABLE, 1, flag, CAP_SET)) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1385 | die("can't add inheritable cap"); |
| 1386 | } |
| 1387 | if (cap_set_proc(caps)) |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1388 | die("can't apply initial cleaned capset"); |
| 1389 | |
| 1390 | /* |
| 1391 | * Instead of dropping bounding set first, do it here in case |
| 1392 | * the caller had a more permissive bounding set which could |
| 1393 | * have been used above to raise a capability that wasn't already |
| 1394 | * present. This requires CAP_SETPCAP, so we raised/kept it above. |
| 1395 | */ |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 1396 | drop_capbset(j->caps, last_valid_cap); |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1397 | |
| 1398 | /* If CAP_SETPCAP wasn't specifically requested, now we remove it. */ |
Kees Cook | e5609ac | 2013-02-06 14:12:41 -0800 | [diff] [blame] | 1399 | if ((j->caps & (one << CAP_SETPCAP)) == 0) { |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1400 | flag[0] = CAP_SETPCAP; |
| 1401 | if (cap_set_flag(caps, CAP_EFFECTIVE, 1, flag, CAP_CLEAR)) |
| 1402 | die("can't clear effective cap"); |
| 1403 | if (cap_set_flag(caps, CAP_PERMITTED, 1, flag, CAP_CLEAR)) |
| 1404 | die("can't clear permitted cap"); |
| 1405 | if (cap_set_flag(caps, CAP_INHERITABLE, 1, flag, CAP_CLEAR)) |
| 1406 | die("can't clear inheritable cap"); |
| 1407 | } |
| 1408 | |
| 1409 | if (cap_set_proc(caps)) |
| 1410 | die("can't apply final cleaned capset"); |
| 1411 | |
Jorge Lucangeli Obes | a6eb21a | 2017-04-20 10:44:00 -0400 | [diff] [blame] | 1412 | /* |
| 1413 | * If ambient capabilities are supported, clear all capabilities first, |
| 1414 | * then raise the requested ones. |
| 1415 | */ |
| 1416 | if (j->flags.set_ambient_caps) { |
| 1417 | if (!cap_ambient_supported()) { |
| 1418 | pdie("ambient capabilities not supported"); |
| 1419 | } |
Jorge Lucangeli Obes | f6058c3 | 2017-04-26 10:26:59 -0400 | [diff] [blame^] | 1420 | if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0) != |
| 1421 | 0) { |
Jorge Lucangeli Obes | a6eb21a | 2017-04-20 10:44:00 -0400 | [diff] [blame] | 1422 | pdie("can't clear ambient capabilities"); |
| 1423 | } |
| 1424 | |
| 1425 | for (i = 0; i < ncaps && i <= last_valid_cap; ++i) { |
| 1426 | if (!(j->caps & (one << i))) |
| 1427 | continue; |
| 1428 | |
| 1429 | if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, i, 0, |
| 1430 | 0) != 0) { |
| 1431 | pdie("prctl(PR_CAP_AMBIENT, " |
| 1432 | "PR_CAP_AMBIENT_RAISE, %u) failed", |
| 1433 | i); |
| 1434 | } |
| 1435 | } |
| 1436 | } |
| 1437 | |
Kees Cook | 323878a | 2013-02-05 15:35:24 -0800 | [diff] [blame] | 1438 | cap_free(caps); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1439 | } |
| 1440 | |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 1441 | static void set_seccomp_filter(const struct minijail *j) |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1442 | { |
| 1443 | /* |
| 1444 | * Set no_new_privs. See </kernel/seccomp.c> and </kernel/sys.c> |
| 1445 | * in the kernel source tree for an explanation of the parameters. |
| 1446 | */ |
| 1447 | if (j->flags.no_new_privs) { |
| 1448 | if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) |
| 1449 | pdie("prctl(PR_SET_NO_NEW_PRIVS)"); |
| 1450 | } |
| 1451 | |
| 1452 | /* |
Jorge Lucangeli Obes | 2413f37 | 2016-04-06 18:43:10 -0700 | [diff] [blame] | 1453 | * Code running with ASan |
| 1454 | * (https://github.com/google/sanitizers/wiki/AddressSanitizer) |
| 1455 | * will make system calls not included in the syscall filter policy, |
| 1456 | * which will likely crash the program. Skip setting seccomp filter in |
| 1457 | * that case. |
| 1458 | * 'running_with_asan()' has no inputs and is completely defined at |
| 1459 | * build time, so this cannot be used by an attacker to skip setting |
| 1460 | * seccomp filter. |
| 1461 | */ |
| 1462 | if (j->flags.seccomp_filter && running_with_asan()) { |
| 1463 | warn("running with ASan, not setting seccomp filter"); |
| 1464 | return; |
| 1465 | } |
| 1466 | |
Jorge Lucangeli Obes | 713f6fb | 2016-10-03 13:03:25 -0400 | [diff] [blame] | 1467 | if (j->flags.seccomp_filter) { |
| 1468 | if (j->flags.seccomp_filter_logging) { |
| 1469 | /* |
| 1470 | * If logging seccomp filter failures, |
| 1471 | * install the SIGSYS handler first. |
| 1472 | */ |
| 1473 | if (install_sigsys_handler()) |
| 1474 | pdie("failed to install SIGSYS handler"); |
| 1475 | warn("logging seccomp filter failures"); |
| 1476 | } else if (j->flags.seccomp_filter_tsync) { |
| 1477 | /* |
| 1478 | * If setting thread sync, |
| 1479 | * reset the SIGSYS signal handler so that |
| 1480 | * the entire thread group is killed. |
| 1481 | */ |
| 1482 | if (signal(SIGSYS, SIG_DFL) == SIG_ERR) |
| 1483 | pdie("failed to reset SIGSYS disposition"); |
| 1484 | info("reset SIGSYS disposition"); |
| 1485 | } |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1486 | } |
| 1487 | |
| 1488 | /* |
| 1489 | * Install the syscall filter. |
| 1490 | */ |
| 1491 | if (j->flags.seccomp_filter) { |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 1492 | if (j->flags.seccomp_filter_tsync) { |
| 1493 | if (sys_seccomp(SECCOMP_SET_MODE_FILTER, |
| 1494 | SECCOMP_FILTER_FLAG_TSYNC, |
| 1495 | j->filter_prog)) { |
| 1496 | pdie("seccomp(tsync) failed"); |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 1497 | } |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 1498 | } else { |
| 1499 | if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, |
| 1500 | j->filter_prog)) { |
| 1501 | pdie("prctl(seccomp_filter) failed"); |
| 1502 | } |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 1503 | } |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1504 | } |
| 1505 | } |
| 1506 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 1507 | void API minijail_enter(const struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1508 | { |
Dylan Reid | f682d47 | 2015-09-17 21:39:07 -0700 | [diff] [blame] | 1509 | /* |
Jorge Lucangeli Obes | 43e29b3 | 2015-12-08 21:07:14 -0800 | [diff] [blame] | 1510 | * If we're dropping caps, get the last valid cap from /proc now, |
| 1511 | * since /proc can be unmounted before drop_caps() is called. |
Dylan Reid | f682d47 | 2015-09-17 21:39:07 -0700 | [diff] [blame] | 1512 | */ |
Jorge Lucangeli Obes | 43e29b3 | 2015-12-08 21:07:14 -0800 | [diff] [blame] | 1513 | unsigned int last_valid_cap = 0; |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 1514 | if (j->flags.capbset_drop || j->flags.use_caps) |
Jorge Lucangeli Obes | 43e29b3 | 2015-12-08 21:07:14 -0800 | [diff] [blame] | 1515 | last_valid_cap = get_last_valid_cap(); |
Dylan Reid | f682d47 | 2015-09-17 21:39:07 -0700 | [diff] [blame] | 1516 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1517 | if (j->flags.pids) |
| 1518 | die("tried to enter a pid-namespaced jail;" |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 1519 | " try minijail_run()?"); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1520 | |
Lutz Justen | 13807cb | 2017-01-03 17:11:55 +0100 | [diff] [blame] | 1521 | if (j->flags.inherit_suppl_gids && !j->user) |
Jorge Lucangeli Obes | 3454319 | 2017-01-11 16:07:57 -0500 | [diff] [blame] | 1522 | die("cannot inherit supplementary groups without setting a " |
| 1523 | "username"); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1524 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1525 | /* |
| 1526 | * We can't recover from failures if we've dropped privileges partially, |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1527 | * so we don't even try. If any of our operations fail, we abort() the |
| 1528 | * entire process. |
| 1529 | */ |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 1530 | if (j->flags.enter_vfs && setns(j->mountns_fd, CLONE_NEWNS)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1531 | pdie("setns(CLONE_NEWNS) failed"); |
Jorge Lucangeli Obes | 1563b5b | 2014-07-10 07:01:53 -0700 | [diff] [blame] | 1532 | |
Jorge Lucangeli Obes | 805be39 | 2015-10-12 15:55:59 -0700 | [diff] [blame] | 1533 | if (j->flags.vfs) { |
Jorge Lucangeli Obes | f7a3868 | 2015-12-04 15:43:30 -0800 | [diff] [blame] | 1534 | if (unshare(CLONE_NEWNS)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1535 | pdie("unshare(CLONE_NEWNS) failed"); |
Jorge Lucangeli Obes | f7a3868 | 2015-12-04 15:43:30 -0800 | [diff] [blame] | 1536 | /* |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 1537 | * Unless asked not to, remount all filesystems as private. |
| 1538 | * If they are shared, new bind mounts will creep out of our |
| 1539 | * namespace. |
Jorge Lucangeli Obes | f7a3868 | 2015-12-04 15:43:30 -0800 | [diff] [blame] | 1540 | * https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt |
| 1541 | */ |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 1542 | if (!j->flags.skip_remount_private) { |
| 1543 | if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1544 | pdie("mount(NULL, /, NULL, MS_REC | MS_PRIVATE," |
| 1545 | " NULL) failed"); |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 1546 | } |
Jorge Lucangeli Obes | f7a3868 | 2015-12-04 15:43:30 -0800 | [diff] [blame] | 1547 | } |
Elly Fong-Jones | 6c08630 | 2013-03-20 17:15:28 -0400 | [diff] [blame] | 1548 | |
Dylan Reid | f794247 | 2015-11-18 17:55:26 -0800 | [diff] [blame] | 1549 | if (j->flags.ipc && unshare(CLONE_NEWIPC)) { |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1550 | pdie("unshare(CLONE_NEWIPC) failed"); |
Dylan Reid | f794247 | 2015-11-18 17:55:26 -0800 | [diff] [blame] | 1551 | } |
| 1552 | |
Dylan Reid | 1102f5a | 2015-09-15 11:52:20 -0700 | [diff] [blame] | 1553 | if (j->flags.enter_net) { |
| 1554 | if (setns(j->netns_fd, CLONE_NEWNET)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1555 | pdie("setns(CLONE_NEWNET) failed"); |
Mike Frysinger | 7559dfe | 2016-11-15 18:58:39 -0500 | [diff] [blame] | 1556 | } else if (j->flags.net) { |
| 1557 | if (unshare(CLONE_NEWNET)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1558 | pdie("unshare(CLONE_NEWNET) failed"); |
| 1559 | config_net_loopback(); |
Dylan Reid | 1102f5a | 2015-09-15 11:52:20 -0700 | [diff] [blame] | 1560 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1561 | |
Dylan Reid | 4cbc2a5 | 2016-06-17 19:06:07 -0700 | [diff] [blame] | 1562 | if (j->flags.ns_cgroups && unshare(CLONE_NEWCGROUP)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1563 | pdie("unshare(CLONE_NEWCGROUP) failed"); |
Dylan Reid | 4cbc2a5 | 2016-06-17 19:06:07 -0700 | [diff] [blame] | 1564 | |
Chirantan Ekbote | 866bb3a | 2017-02-07 12:26:42 -0800 | [diff] [blame] | 1565 | if (j->flags.new_session_keyring) { |
| 1566 | if (syscall(SYS_keyctl, KEYCTL_JOIN_SESSION_KEYRING, NULL) < 0) |
| 1567 | pdie("keyctl(KEYCTL_JOIN_SESSION_KEYRING) failed"); |
| 1568 | } |
| 1569 | |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 1570 | if (j->flags.chroot && enter_chroot(j)) |
| 1571 | pdie("chroot"); |
| 1572 | |
Yu-Hsi Chiang | 64d65a7 | 2015-08-13 17:43:27 +0800 | [diff] [blame] | 1573 | if (j->flags.pivot_root && enter_pivot_root(j)) |
| 1574 | pdie("pivot_root"); |
| 1575 | |
Martin Pelikán | ab9eb44 | 2017-01-25 11:53:58 +1100 | [diff] [blame] | 1576 | if (j->flags.mount_tmp && mount_tmp(j)) |
Lee Campbell | 11af062 | 2014-05-22 12:36:04 -0700 | [diff] [blame] | 1577 | pdie("mount_tmp"); |
| 1578 | |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 1579 | if (j->flags.remount_proc_ro && remount_proc_readonly(j)) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1580 | pdie("remount"); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1581 | |
Jorge Lucangeli Obes | f9fcdbe | 2016-02-19 15:04:09 -0800 | [diff] [blame] | 1582 | /* |
| 1583 | * If we're only dropping capabilities from the bounding set, but not |
| 1584 | * from the thread's (permitted|inheritable|effective) sets, do it now. |
| 1585 | */ |
| 1586 | if (j->flags.capbset_drop) { |
| 1587 | drop_capbset(j->cap_bset, last_valid_cap); |
| 1588 | } |
| 1589 | |
| 1590 | if (j->flags.use_caps) { |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1591 | /* |
| 1592 | * POSIX capabilities are a bit tricky. If we drop our |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1593 | * capability to change uids, our attempt to use setuid() |
| 1594 | * below will fail. Hang on to root caps across setuid(), then |
| 1595 | * lock securebits. |
| 1596 | */ |
| 1597 | if (prctl(PR_SET_KEEPCAPS, 1)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1598 | pdie("prctl(PR_SET_KEEPCAPS) failed"); |
Jorge Lucangeli Obes | f783b52 | 2016-03-14 14:34:10 -0700 | [diff] [blame] | 1599 | |
Jorge Lucangeli Obes | 0b20877 | 2017-04-19 14:15:46 -0400 | [diff] [blame] | 1600 | if (lock_securebits() < 0) { |
| 1601 | pdie("locking securebits failed"); |
Jorge Lucangeli Obes | f783b52 | 2016-03-14 14:34:10 -0700 | [diff] [blame] | 1602 | } |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1603 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1604 | |
Jorge Lucangeli Obes | c2c9bcc | 2012-05-01 09:30:24 -0700 | [diff] [blame] | 1605 | if (j->flags.no_new_privs) { |
Jorge Lucangeli Obes | d8c8205 | 2016-02-25 16:00:32 -0800 | [diff] [blame] | 1606 | /* |
| 1607 | * If we're setting no_new_privs, we can drop privileges |
| 1608 | * before setting seccomp filter. This way filter policies |
| 1609 | * don't need to allow privilege-dropping syscalls. |
| 1610 | */ |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1611 | drop_ugid(j); |
Jorge Lucangeli Obes | d8c8205 | 2016-02-25 16:00:32 -0800 | [diff] [blame] | 1612 | drop_caps(j, last_valid_cap); |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1613 | set_seccomp_filter(j); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1614 | } else { |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1615 | /* |
| 1616 | * If we're not setting no_new_privs, |
| 1617 | * we need to set seccomp filter *before* dropping privileges. |
| 1618 | * WARNING: this means that filter policies *must* allow |
| 1619 | * setgroups()/setresgid()/setresuid() for dropping root and |
| 1620 | * capget()/capset()/prctl() for dropping caps. |
| 1621 | */ |
| 1622 | set_seccomp_filter(j); |
Jorge Lucangeli Obes | 6201cf5 | 2012-08-23 11:42:27 -0700 | [diff] [blame] | 1623 | drop_ugid(j); |
Jorge Lucangeli Obes | d8c8205 | 2016-02-25 16:00:32 -0800 | [diff] [blame] | 1624 | drop_caps(j, last_valid_cap); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1625 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1626 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1627 | /* |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 1628 | * Select the specified alternate syscall table. The table must not |
| 1629 | * block prctl(2) if we're using seccomp as well. |
| 1630 | */ |
| 1631 | if (j->flags.alt_syscall) { |
| 1632 | if (prctl(PR_ALT_SYSCALL, 1, j->alt_syscall_table)) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1633 | pdie("prctl(PR_ALT_SYSCALL) failed"); |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 1634 | } |
| 1635 | |
| 1636 | /* |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1637 | * seccomp has to come last since it cuts off all the other |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1638 | * privilege-dropping syscalls :) |
| 1639 | */ |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 1640 | if (j->flags.seccomp && prctl(PR_SET_SECCOMP, 1)) { |
Jorge Lucangeli Obes | 7b2e29c | 2016-08-04 12:21:03 -0400 | [diff] [blame] | 1641 | if ((errno == EINVAL) && seccomp_can_softfail()) { |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 1642 | warn("seccomp not supported"); |
| 1643 | return; |
| 1644 | } |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1645 | pdie("prctl(PR_SET_SECCOMP) failed"); |
Utkarsh Sanghi | 0ef8a66 | 2014-08-18 15:50:11 -0700 | [diff] [blame] | 1646 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1647 | } |
| 1648 | |
Jorge Lucangeli Obes | db0bc67 | 2016-08-03 10:45:21 -0400 | [diff] [blame] | 1649 | /* TODO(wad): will visibility affect this variable? */ |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1650 | static int init_exitstatus = 0; |
| 1651 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 1652 | void init_term(int __attribute__ ((unused)) sig) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1653 | { |
| 1654 | _exit(init_exitstatus); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1655 | } |
| 1656 | |
Jorge Lucangeli Obes | 963eeec | 2016-08-10 16:02:43 -0400 | [diff] [blame] | 1657 | void init(pid_t rootpid) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1658 | { |
| 1659 | pid_t pid; |
| 1660 | int status; |
Jorge Lucangeli Obes | db0bc67 | 2016-08-03 10:45:21 -0400 | [diff] [blame] | 1661 | /* So that we exit with the right status. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1662 | signal(SIGTERM, init_term); |
Jorge Lucangeli Obes | db0bc67 | 2016-08-03 10:45:21 -0400 | [diff] [blame] | 1663 | /* TODO(wad): self jail with seccomp filters here. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1664 | while ((pid = wait(&status)) > 0) { |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1665 | /* |
| 1666 | * This loop will only end when either there are no processes |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1667 | * left inside our pid namespace or we get a signal. |
| 1668 | */ |
| 1669 | if (pid == rootpid) |
| 1670 | init_exitstatus = status; |
| 1671 | } |
| 1672 | if (!WIFEXITED(init_exitstatus)) |
| 1673 | _exit(MINIJAIL_ERR_INIT); |
| 1674 | _exit(WEXITSTATUS(init_exitstatus)); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1675 | } |
| 1676 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 1677 | int API minijail_from_fd(int fd, struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1678 | { |
| 1679 | size_t sz = 0; |
| 1680 | size_t bytes = read(fd, &sz, sizeof(sz)); |
| 1681 | char *buf; |
| 1682 | int r; |
| 1683 | if (sizeof(sz) != bytes) |
| 1684 | return -EINVAL; |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1685 | if (sz > USHRT_MAX) /* arbitrary sanity check */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1686 | return -E2BIG; |
| 1687 | buf = malloc(sz); |
| 1688 | if (!buf) |
| 1689 | return -ENOMEM; |
| 1690 | bytes = read(fd, buf, sz); |
| 1691 | if (bytes != sz) { |
| 1692 | free(buf); |
| 1693 | return -EINVAL; |
| 1694 | } |
| 1695 | r = minijail_unmarshal(j, buf, sz); |
| 1696 | free(buf); |
| 1697 | return r; |
Will Drewry | 2f54b6a | 2011-09-16 13:45:31 -0500 | [diff] [blame] | 1698 | } |
| 1699 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 1700 | int API minijail_to_fd(struct minijail *j, int fd) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1701 | { |
| 1702 | char *buf; |
| 1703 | size_t sz = minijail_size(j); |
| 1704 | ssize_t written; |
| 1705 | int r; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1706 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1707 | if (!sz) |
| 1708 | return -EINVAL; |
| 1709 | buf = malloc(sz); |
| 1710 | r = minijail_marshal(j, buf, sz); |
| 1711 | if (r) { |
| 1712 | free(buf); |
| 1713 | return r; |
| 1714 | } |
| 1715 | /* Sends [size][minijail]. */ |
| 1716 | written = write(fd, &sz, sizeof(sz)); |
| 1717 | if (written != sizeof(sz)) { |
| 1718 | free(buf); |
| 1719 | return -EFAULT; |
| 1720 | } |
| 1721 | written = write(fd, buf, sz); |
| 1722 | if (written < 0 || (size_t) written != sz) { |
| 1723 | free(buf); |
| 1724 | return -EFAULT; |
| 1725 | } |
| 1726 | free(buf); |
| 1727 | return 0; |
Will Drewry | 2f54b6a | 2011-09-16 13:45:31 -0500 | [diff] [blame] | 1728 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1729 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 1730 | int setup_preload(void) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1731 | { |
Daniel Erat | 5b7a318 | 2015-08-19 16:06:22 -0600 | [diff] [blame] | 1732 | #if defined(__ANDROID__) |
Jorge Lucangeli Obes | 0b20877 | 2017-04-19 14:15:46 -0400 | [diff] [blame] | 1733 | /* Don't use LDPRELOAD on Android. */ |
Jorge Lucangeli Obes | a21c8fc | 2015-07-15 16:22:34 -0700 | [diff] [blame] | 1734 | return 0; |
| 1735 | #else |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1736 | char *oldenv = getenv(kLdPreloadEnvVar) ? : ""; |
| 1737 | char *newenv = malloc(strlen(oldenv) + 2 + strlen(PRELOADPATH)); |
| 1738 | if (!newenv) |
| 1739 | return -ENOMEM; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1740 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1741 | /* Only insert a separating space if we have something to separate... */ |
| 1742 | sprintf(newenv, "%s%s%s", oldenv, strlen(oldenv) ? " " : "", |
| 1743 | PRELOADPATH); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1744 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1745 | /* setenv() makes a copy of the string we give it. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1746 | setenv(kLdPreloadEnvVar, newenv, 1); |
| 1747 | free(newenv); |
| 1748 | return 0; |
Jorge Lucangeli Obes | a21c8fc | 2015-07-15 16:22:34 -0700 | [diff] [blame] | 1749 | #endif |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1750 | } |
| 1751 | |
Jorge Lucangeli Obes | 0b20877 | 2017-04-19 14:15:46 -0400 | [diff] [blame] | 1752 | static int setup_pipe(int fds[2]) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1753 | { |
| 1754 | int r = pipe(fds); |
| 1755 | char fd_buf[11]; |
| 1756 | if (r) |
| 1757 | return r; |
| 1758 | r = snprintf(fd_buf, sizeof(fd_buf), "%d", fds[0]); |
| 1759 | if (r <= 0) |
| 1760 | return -EINVAL; |
| 1761 | setenv(kFdEnvVar, fd_buf, 1); |
| 1762 | return 0; |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 1763 | } |
| 1764 | |
Jorge Lucangeli Obes | 0b20877 | 2017-04-19 14:15:46 -0400 | [diff] [blame] | 1765 | static int close_open_fds(int *inheritable_fds, size_t size) |
Luis Hector Chavez | 43ff080 | 2016-10-07 12:21:07 -0700 | [diff] [blame] | 1766 | { |
| 1767 | const char *kFdPath = "/proc/self/fd"; |
| 1768 | |
| 1769 | DIR *d = opendir(kFdPath); |
| 1770 | struct dirent *dir_entry; |
| 1771 | |
| 1772 | if (d == NULL) |
| 1773 | return -1; |
| 1774 | int dir_fd = dirfd(d); |
| 1775 | while ((dir_entry = readdir(d)) != NULL) { |
| 1776 | size_t i; |
| 1777 | char *end; |
| 1778 | bool should_close = true; |
| 1779 | const int fd = strtol(dir_entry->d_name, &end, 10); |
| 1780 | |
| 1781 | if ((*end) != '\0') { |
| 1782 | continue; |
| 1783 | } |
| 1784 | /* |
| 1785 | * We might have set up some pipes that we want to share with |
| 1786 | * the parent process, and should not be closed. |
| 1787 | */ |
| 1788 | for (i = 0; i < size; ++i) { |
| 1789 | if (fd == inheritable_fds[i]) { |
| 1790 | should_close = false; |
| 1791 | break; |
| 1792 | } |
| 1793 | } |
| 1794 | /* Also avoid closing the directory fd. */ |
| 1795 | if (should_close && fd != dir_fd) |
| 1796 | close(fd); |
| 1797 | } |
| 1798 | closedir(d); |
| 1799 | return 0; |
| 1800 | } |
| 1801 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1802 | int minijail_run_internal(struct minijail *j, const char *filename, |
| 1803 | char *const argv[], pid_t *pchild_pid, |
| 1804 | int *pstdin_fd, int *pstdout_fd, int *pstderr_fd, |
| 1805 | int use_preload); |
| 1806 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 1807 | int API minijail_run(struct minijail *j, const char *filename, |
| 1808 | char *const argv[]) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1809 | { |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1810 | return minijail_run_internal(j, filename, argv, NULL, NULL, NULL, NULL, |
| 1811 | true); |
Jorge Lucangeli Obes | 9807d03 | 2012-04-17 13:36:00 -0700 | [diff] [blame] | 1812 | } |
| 1813 | |
| 1814 | int API minijail_run_pid(struct minijail *j, const char *filename, |
| 1815 | char *const argv[], pid_t *pchild_pid) |
| 1816 | { |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1817 | return minijail_run_internal(j, filename, argv, pchild_pid, |
| 1818 | NULL, NULL, NULL, true); |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 1819 | } |
| 1820 | |
| 1821 | int API minijail_run_pipe(struct minijail *j, const char *filename, |
Jorge Lucangeli Obes | 6537a56 | 2012-09-05 10:39:40 -0700 | [diff] [blame] | 1822 | char *const argv[], int *pstdin_fd) |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 1823 | { |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1824 | return minijail_run_internal(j, filename, argv, NULL, pstdin_fd, |
| 1825 | NULL, NULL, true); |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 1826 | } |
| 1827 | |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 1828 | int API minijail_run_pid_pipes(struct minijail *j, const char *filename, |
Jorge Lucangeli Obes | 4ae30cc | 2014-04-10 15:35:33 -0700 | [diff] [blame] | 1829 | char *const argv[], pid_t *pchild_pid, |
| 1830 | int *pstdin_fd, int *pstdout_fd, int *pstderr_fd) |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 1831 | { |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1832 | return minijail_run_internal(j, filename, argv, pchild_pid, |
| 1833 | pstdin_fd, pstdout_fd, pstderr_fd, true); |
| 1834 | } |
| 1835 | |
| 1836 | int API minijail_run_no_preload(struct minijail *j, const char *filename, |
| 1837 | char *const argv[]) |
| 1838 | { |
| 1839 | return minijail_run_internal(j, filename, argv, NULL, NULL, NULL, NULL, |
| 1840 | false); |
| 1841 | } |
| 1842 | |
Samuel Tan | 63187f4 | 2015-10-16 13:01:53 -0700 | [diff] [blame] | 1843 | int API minijail_run_pid_pipes_no_preload(struct minijail *j, |
Jorge Lucangeli Obes | 43a6a86 | 2015-12-04 14:53:36 -0800 | [diff] [blame] | 1844 | const char *filename, |
| 1845 | char *const argv[], |
Samuel Tan | 63187f4 | 2015-10-16 13:01:53 -0700 | [diff] [blame] | 1846 | pid_t *pchild_pid, |
Jorge Lucangeli Obes | 43a6a86 | 2015-12-04 14:53:36 -0800 | [diff] [blame] | 1847 | int *pstdin_fd, int *pstdout_fd, |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 1848 | int *pstderr_fd) |
| 1849 | { |
Samuel Tan | 63187f4 | 2015-10-16 13:01:53 -0700 | [diff] [blame] | 1850 | return minijail_run_internal(j, filename, argv, pchild_pid, |
| 1851 | pstdin_fd, pstdout_fd, pstderr_fd, false); |
| 1852 | } |
| 1853 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1854 | int minijail_run_internal(struct minijail *j, const char *filename, |
| 1855 | char *const argv[], pid_t *pchild_pid, |
| 1856 | int *pstdin_fd, int *pstdout_fd, int *pstderr_fd, |
| 1857 | int use_preload) |
| 1858 | { |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1859 | char *oldenv, *oldenv_copy = NULL; |
| 1860 | pid_t child_pid; |
| 1861 | int pipe_fds[2]; |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 1862 | int stdin_fds[2]; |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 1863 | int stdout_fds[2]; |
| 1864 | int stderr_fds[2]; |
Dylan Reid | ce5b55e | 2016-01-13 11:04:16 -0800 | [diff] [blame] | 1865 | int child_sync_pipe_fds[2]; |
| 1866 | int sync_child = 0; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1867 | int ret; |
Elly Jones | a05d7bb | 2012-06-14 14:09:27 -0400 | [diff] [blame] | 1868 | /* We need to remember this across the minijail_preexec() call. */ |
| 1869 | int pid_namespace = j->flags.pids; |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 1870 | int do_init = j->flags.do_init; |
Ben Chan | 541c7e5 | 2011-08-26 14:55:53 -0700 | [diff] [blame] | 1871 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1872 | if (use_preload) { |
| 1873 | oldenv = getenv(kLdPreloadEnvVar); |
| 1874 | if (oldenv) { |
| 1875 | oldenv_copy = strdup(oldenv); |
| 1876 | if (!oldenv_copy) |
| 1877 | return -ENOMEM; |
| 1878 | } |
| 1879 | |
| 1880 | if (setup_preload()) |
| 1881 | return -EFAULT; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 1882 | } |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 1883 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1884 | if (!use_preload) { |
Jorge Lucangeli Obes | a205390 | 2016-08-02 12:08:15 -0400 | [diff] [blame] | 1885 | if (j->flags.use_caps && j->caps != 0) |
Jorge Lucangeli Obes | 457a5e3 | 2016-11-23 15:18:56 -0500 | [diff] [blame] | 1886 | die("non-empty capabilities are not supported without " |
| 1887 | "LD_PRELOAD"); |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1888 | } |
Will Drewry | 2f54b6a | 2011-09-16 13:45:31 -0500 | [diff] [blame] | 1889 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 1890 | /* |
Jorge Lucangeli Obes | aa235b9 | 2016-11-23 13:48:15 -0500 | [diff] [blame] | 1891 | * Make the process group ID of this process equal to its PID. |
| 1892 | * In the non-interactive case (e.g. when the parent process is started |
| 1893 | * from init) this ensures the parent process and the jailed process |
| 1894 | * can be killed together. |
| 1895 | * When the parent process is started from the console this ensures |
| 1896 | * the call to setsid(2) in the jailed process succeeds. |
| 1897 | * |
Jorge Lucangeli Obes | 3c84df1 | 2015-05-14 17:37:58 -0700 | [diff] [blame] | 1898 | * Don't fail on EPERM, since setpgid(0, 0) can only EPERM when |
| 1899 | * the process is already a process group leader. |
| 1900 | */ |
| 1901 | if (setpgid(0 /* use calling PID */, 0 /* make PGID = PID */)) { |
| 1902 | if (errno != EPERM) { |
Jorge Lucangeli Obes | aa235b9 | 2016-11-23 13:48:15 -0500 | [diff] [blame] | 1903 | pdie("setpgid(0, 0) failed"); |
Jorge Lucangeli Obes | 3c84df1 | 2015-05-14 17:37:58 -0700 | [diff] [blame] | 1904 | } |
| 1905 | } |
| 1906 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 1907 | if (use_preload) { |
| 1908 | /* |
| 1909 | * Before we fork(2) and execve(2) the child process, we need |
| 1910 | * to open a pipe(2) to send the minijail configuration over. |
| 1911 | */ |
| 1912 | if (setup_pipe(pipe_fds)) |
| 1913 | return -EFAULT; |
| 1914 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 1915 | |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 1916 | /* |
| 1917 | * If we want to write to the child process' standard input, |
| 1918 | * create the pipe(2) now. |
| 1919 | */ |
| 1920 | if (pstdin_fd) { |
| 1921 | if (pipe(stdin_fds)) |
| 1922 | return -EFAULT; |
| 1923 | } |
| 1924 | |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 1925 | /* |
| 1926 | * If we want to read from the child process' standard output, |
| 1927 | * create the pipe(2) now. |
| 1928 | */ |
| 1929 | if (pstdout_fd) { |
| 1930 | if (pipe(stdout_fds)) |
| 1931 | return -EFAULT; |
| 1932 | } |
| 1933 | |
| 1934 | /* |
| 1935 | * If we want to read from the child process' standard error, |
| 1936 | * create the pipe(2) now. |
| 1937 | */ |
| 1938 | if (pstderr_fd) { |
| 1939 | if (pipe(stderr_fds)) |
| 1940 | return -EFAULT; |
| 1941 | } |
| 1942 | |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 1943 | /* |
Jorge Lucangeli Obes | ab6fa6f | 2016-08-04 15:42:48 -0400 | [diff] [blame] | 1944 | * If we want to set up a new uid/gid map in the user namespace, |
Jorge Lucangeli Obes | b8a5138 | 2016-01-25 20:08:22 -0800 | [diff] [blame] | 1945 | * or if we need to add the child process to cgroups, create the pipe(2) |
| 1946 | * to sync between parent and child. |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 1947 | */ |
Jorge Lucangeli Obes | b8a5138 | 2016-01-25 20:08:22 -0800 | [diff] [blame] | 1948 | if (j->flags.userns || j->flags.cgroups) { |
Dylan Reid | ce5b55e | 2016-01-13 11:04:16 -0800 | [diff] [blame] | 1949 | sync_child = 1; |
| 1950 | if (pipe(child_sync_pipe_fds)) |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 1951 | return -EFAULT; |
| 1952 | } |
| 1953 | |
Jorge Lucangeli Obes | d0a6e2f | 2015-11-24 14:21:21 -0800 | [diff] [blame] | 1954 | /* |
| 1955 | * Use sys_clone() if and only if we're creating a pid namespace. |
Elly Jones | 761b741 | 2012-06-13 15:49:52 -0400 | [diff] [blame] | 1956 | * |
| 1957 | * tl;dr: WARNING: do not mix pid namespaces and multithreading. |
| 1958 | * |
| 1959 | * In multithreaded programs, there are a bunch of locks inside libc, |
| 1960 | * some of which may be held by other threads at the time that we call |
| 1961 | * minijail_run_pid(). If we call fork(), glibc does its level best to |
| 1962 | * ensure that we hold all of these locks before it calls clone() |
| 1963 | * internally and drop them after clone() returns, but when we call |
| 1964 | * sys_clone(2) directly, all that gets bypassed and we end up with a |
| 1965 | * child address space where some of libc's important locks are held by |
| 1966 | * other threads (which did not get cloned, and hence will never release |
| 1967 | * those locks). This is okay so long as we call exec() immediately |
| 1968 | * after, but a bunch of seemingly-innocent libc functions like setenv() |
| 1969 | * take locks. |
| 1970 | * |
| 1971 | * Hence, only call sys_clone() if we need to, in order to get at pid |
| 1972 | * namespacing. If we follow this path, the child's address space might |
| 1973 | * have broken locks; you may only call functions that do not acquire |
| 1974 | * any locks. |
| 1975 | * |
| 1976 | * Unfortunately, fork() acquires every lock it can get its hands on, as |
| 1977 | * previously detailed, so this function is highly likely to deadlock |
| 1978 | * later on (see "deadlock here") if we're multithreaded. |
| 1979 | * |
| 1980 | * We might hack around this by having the clone()d child (init of the |
| 1981 | * pid namespace) return directly, rather than leaving the clone()d |
| 1982 | * process hanging around to be init for the new namespace (and having |
Jorge Lucangeli Obes | a521bee | 2016-03-03 13:47:57 -0800 | [diff] [blame] | 1983 | * its fork()ed child return in turn), but that process would be |
| 1984 | * crippled with its libc locks potentially broken. We might try |
| 1985 | * fork()ing in the parent before we clone() to ensure that we own all |
| 1986 | * the locks, but then we have to have the forked child hanging around |
| 1987 | * consuming resources (and possibly having file descriptors / shared |
| 1988 | * memory regions / etc attached). We'd need to keep the child around to |
| 1989 | * avoid having its children get reparented to init. |
Elly Jones | 761b741 | 2012-06-13 15:49:52 -0400 | [diff] [blame] | 1990 | * |
| 1991 | * TODO(ellyjones): figure out if the "forked child hanging around" |
| 1992 | * problem is fixable or not. It would be nice if we worked in this |
| 1993 | * case. |
| 1994 | */ |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 1995 | if (pid_namespace) { |
| 1996 | int clone_flags = CLONE_NEWPID | SIGCHLD; |
| 1997 | if (j->flags.userns) |
| 1998 | clone_flags |= CLONE_NEWUSER; |
| 1999 | child_pid = syscall(SYS_clone, clone_flags, NULL); |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2000 | } else { |
Elly Jones | 761b741 | 2012-06-13 15:49:52 -0400 | [diff] [blame] | 2001 | child_pid = fork(); |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2002 | } |
Elly Jones | 761b741 | 2012-06-13 15:49:52 -0400 | [diff] [blame] | 2003 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2004 | if (child_pid < 0) { |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2005 | if (use_preload) { |
| 2006 | free(oldenv_copy); |
| 2007 | } |
Lee Campbell | 1e4fc6a | 2014-06-06 17:40:02 -0700 | [diff] [blame] | 2008 | die("failed to fork child"); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2009 | } |
Will Drewry | f89aef5 | 2011-09-16 16:48:57 -0500 | [diff] [blame] | 2010 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2011 | if (child_pid) { |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2012 | if (use_preload) { |
| 2013 | /* Restore parent's LD_PRELOAD. */ |
| 2014 | if (oldenv_copy) { |
| 2015 | setenv(kLdPreloadEnvVar, oldenv_copy, 1); |
| 2016 | free(oldenv_copy); |
| 2017 | } else { |
| 2018 | unsetenv(kLdPreloadEnvVar); |
| 2019 | } |
| 2020 | unsetenv(kFdEnvVar); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2021 | } |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2022 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2023 | j->initpid = child_pid; |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2024 | |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 2025 | if (j->flags.pid_file) |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 2026 | write_pid_file_or_die(j); |
Yu-Hsi Chiang | 3cc05ea | 2015-08-11 11:23:17 +0800 | [diff] [blame] | 2027 | |
Jorge Lucangeli Obes | b8a5138 | 2016-01-25 20:08:22 -0800 | [diff] [blame] | 2028 | if (j->flags.cgroups) |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 2029 | add_to_cgroups_or_die(j); |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 2030 | |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 2031 | if (j->flags.userns) |
Jorge Lucangeli Obes | f205fff | 2016-08-06 09:06:21 -0400 | [diff] [blame] | 2032 | write_ugid_maps_or_die(j); |
Dylan Reid | ce5b55e | 2016-01-13 11:04:16 -0800 | [diff] [blame] | 2033 | |
| 2034 | if (sync_child) |
| 2035 | parent_setup_complete(child_sync_pipe_fds); |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 2036 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2037 | if (use_preload) { |
| 2038 | /* Send marshalled minijail. */ |
| 2039 | close(pipe_fds[0]); /* read endpoint */ |
| 2040 | ret = minijail_to_fd(j, pipe_fds[1]); |
| 2041 | close(pipe_fds[1]); /* write endpoint */ |
| 2042 | if (ret) { |
| 2043 | kill(j->initpid, SIGKILL); |
| 2044 | die("failed to send marshalled minijail"); |
| 2045 | } |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2046 | } |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2047 | |
Jorge Lucangeli Obes | 9807d03 | 2012-04-17 13:36:00 -0700 | [diff] [blame] | 2048 | if (pchild_pid) |
| 2049 | *pchild_pid = child_pid; |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2050 | |
| 2051 | /* |
| 2052 | * If we want to write to the child process' standard input, |
| 2053 | * set up the write end of the pipe. |
| 2054 | */ |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 2055 | if (pstdin_fd) |
| 2056 | *pstdin_fd = setup_pipe_end(stdin_fds, |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2057 | 1 /* write end */); |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 2058 | |
| 2059 | /* |
| 2060 | * If we want to read from the child process' standard output, |
| 2061 | * set up the read end of the pipe. |
| 2062 | */ |
| 2063 | if (pstdout_fd) |
| 2064 | *pstdout_fd = setup_pipe_end(stdout_fds, |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2065 | 0 /* read end */); |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 2066 | |
| 2067 | /* |
| 2068 | * If we want to read from the child process' standard error, |
| 2069 | * set up the read end of the pipe. |
| 2070 | */ |
| 2071 | if (pstderr_fd) |
| 2072 | *pstderr_fd = setup_pipe_end(stderr_fds, |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2073 | 0 /* read end */); |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2074 | |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2075 | return 0; |
| 2076 | } |
Jorge Lucangeli Obes | a205390 | 2016-08-02 12:08:15 -0400 | [diff] [blame] | 2077 | /* Child process. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2078 | free(oldenv_copy); |
Ben Chan | 541c7e5 | 2011-08-26 14:55:53 -0700 | [diff] [blame] | 2079 | |
Peter Qiu | 2860c46 | 2015-12-16 15:13:06 -0800 | [diff] [blame] | 2080 | if (j->flags.reset_signal_mask) { |
| 2081 | sigset_t signal_mask; |
| 2082 | if (sigemptyset(&signal_mask) != 0) |
| 2083 | pdie("sigemptyset failed"); |
| 2084 | if (sigprocmask(SIG_SETMASK, &signal_mask, NULL) != 0) |
| 2085 | pdie("sigprocmask failed"); |
| 2086 | } |
| 2087 | |
Luis Hector Chavez | 43ff080 | 2016-10-07 12:21:07 -0700 | [diff] [blame] | 2088 | if (j->flags.close_open_fds) { |
| 2089 | const size_t kMaxInheritableFdsSize = 10; |
| 2090 | int inheritable_fds[kMaxInheritableFdsSize]; |
| 2091 | size_t size = 0; |
| 2092 | if (use_preload) { |
| 2093 | inheritable_fds[size++] = pipe_fds[0]; |
| 2094 | inheritable_fds[size++] = pipe_fds[1]; |
| 2095 | } |
| 2096 | if (sync_child) { |
| 2097 | inheritable_fds[size++] = child_sync_pipe_fds[0]; |
| 2098 | inheritable_fds[size++] = child_sync_pipe_fds[1]; |
| 2099 | } |
| 2100 | if (pstdin_fd) { |
| 2101 | inheritable_fds[size++] = stdin_fds[0]; |
| 2102 | inheritable_fds[size++] = stdin_fds[1]; |
| 2103 | } |
| 2104 | if (pstdout_fd) { |
| 2105 | inheritable_fds[size++] = stdout_fds[0]; |
| 2106 | inheritable_fds[size++] = stdout_fds[1]; |
| 2107 | } |
| 2108 | if (pstderr_fd) { |
| 2109 | inheritable_fds[size++] = stderr_fds[0]; |
| 2110 | inheritable_fds[size++] = stderr_fds[1]; |
| 2111 | } |
| 2112 | |
| 2113 | if (close_open_fds(inheritable_fds, size) < 0) |
| 2114 | die("failed to close open file descriptors"); |
| 2115 | } |
| 2116 | |
Dylan Reid | ce5b55e | 2016-01-13 11:04:16 -0800 | [diff] [blame] | 2117 | if (sync_child) |
| 2118 | wait_for_parent_setup(child_sync_pipe_fds); |
| 2119 | |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 2120 | if (j->flags.userns) |
Dylan Reid | ce5b55e | 2016-01-13 11:04:16 -0800 | [diff] [blame] | 2121 | enter_user_namespace(j); |
Yu-Hsi Chiang | 10e9123 | 2015-08-05 14:40:45 +0800 | [diff] [blame] | 2122 | |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2123 | /* |
| 2124 | * If we want to write to the jailed process' standard input, |
| 2125 | * set up the read end of the pipe. |
| 2126 | */ |
| 2127 | if (pstdin_fd) { |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 2128 | if (setup_and_dupe_pipe_end(stdin_fds, 0 /* read end */, |
| 2129 | STDIN_FILENO) < 0) |
Jorge Lucangeli Obes | df4bd35 | 2012-08-29 19:12:28 -0700 | [diff] [blame] | 2130 | die("failed to set up stdin pipe"); |
| 2131 | } |
| 2132 | |
Jorge Lucangeli Obes | 339a113 | 2013-02-15 16:53:47 -0800 | [diff] [blame] | 2133 | /* |
| 2134 | * If we want to read from the jailed process' standard output, |
| 2135 | * set up the write end of the pipe. |
| 2136 | */ |
| 2137 | if (pstdout_fd) { |
| 2138 | if (setup_and_dupe_pipe_end(stdout_fds, 1 /* write end */, |
| 2139 | STDOUT_FILENO) < 0) |
| 2140 | die("failed to set up stdout pipe"); |
| 2141 | } |
| 2142 | |
| 2143 | /* |
| 2144 | * If we want to read from the jailed process' standard error, |
| 2145 | * set up the write end of the pipe. |
| 2146 | */ |
| 2147 | if (pstderr_fd) { |
| 2148 | if (setup_and_dupe_pipe_end(stderr_fds, 1 /* write end */, |
| 2149 | STDERR_FILENO) < 0) |
| 2150 | die("failed to set up stderr pipe"); |
| 2151 | } |
| 2152 | |
Jorge Lucangeli Obes | aa235b9 | 2016-11-23 13:48:15 -0500 | [diff] [blame] | 2153 | /* |
| 2154 | * If any of stdin, stdout, or stderr are TTYs, create a new session. |
| 2155 | * This prevents the jailed process from using the TIOCSTI ioctl |
| 2156 | * to push characters into the parent process terminal's input buffer, |
| 2157 | * therefore escaping the jail. |
| 2158 | */ |
| 2159 | if (isatty(STDIN_FILENO) || isatty(STDOUT_FILENO) || |
| 2160 | isatty(STDERR_FILENO)) { |
| 2161 | if (setsid() < 0) { |
| 2162 | pdie("setsid() failed"); |
| 2163 | } |
| 2164 | } |
| 2165 | |
Dylan Reid | 791f577 | 2015-09-14 20:02:42 -0700 | [diff] [blame] | 2166 | /* If running an init program, let it decide when/how to mount /proc. */ |
| 2167 | if (pid_namespace && !do_init) |
| 2168 | j->flags.remount_proc_ro = 0; |
| 2169 | |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2170 | if (use_preload) { |
| 2171 | /* Strip out flags that cannot be inherited across execve(2). */ |
| 2172 | minijail_preexec(j); |
| 2173 | } else { |
Jorge Lucangeli Obes | a205390 | 2016-08-02 12:08:15 -0400 | [diff] [blame] | 2174 | /* |
| 2175 | * If not using LD_PRELOAD, do all jailing before execve(2). |
| 2176 | * Note that PID namespaces can only be entered on fork(2), |
| 2177 | * so that flag is still cleared. |
| 2178 | */ |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2179 | j->flags.pids = 0; |
| 2180 | } |
Jorge Lucangeli Obes | a205390 | 2016-08-02 12:08:15 -0400 | [diff] [blame] | 2181 | /* Jail this process, then execve(2) the target. */ |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2182 | minijail_enter(j); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2183 | |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 2184 | if (pid_namespace && do_init) { |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 2185 | /* |
| 2186 | * pid namespace: this process will become init inside the new |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 2187 | * namespace. We don't want all programs we might exec to have |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2188 | * to know how to be init. Normally (do_init == 1) we fork off |
Yu-Hsi Chiang | 3e954ec | 2015-07-28 16:48:14 +0800 | [diff] [blame] | 2189 | * a child to actually run the program. If |do_init == 0|, we |
| 2190 | * let the program keep pid 1 and be init. |
Elly Jones | 761b741 | 2012-06-13 15:49:52 -0400 | [diff] [blame] | 2191 | * |
| 2192 | * If we're multithreaded, we'll probably deadlock here. See |
| 2193 | * WARNING above. |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2194 | */ |
| 2195 | child_pid = fork(); |
Jorge Lucangeli Obes | 963eeec | 2016-08-10 16:02:43 -0400 | [diff] [blame] | 2196 | if (child_pid < 0) { |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2197 | _exit(child_pid); |
Jorge Lucangeli Obes | 963eeec | 2016-08-10 16:02:43 -0400 | [diff] [blame] | 2198 | } else if (child_pid > 0) { |
Jorge Lucangeli Obes | 1365061 | 2016-09-02 11:27:29 -0400 | [diff] [blame] | 2199 | /* |
| 2200 | * Best effort. Don't bother checking the return value. |
| 2201 | */ |
Jorge Lucangeli Obes | 963eeec | 2016-08-10 16:02:43 -0400 | [diff] [blame] | 2202 | prctl(PR_SET_NAME, "minijail-init"); |
| 2203 | init(child_pid); /* Never returns. */ |
| 2204 | } |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2205 | } |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2206 | |
Elly Jones | dd3e851 | 2012-01-23 15:13:38 -0500 | [diff] [blame] | 2207 | /* |
Jorge Lucangeli Obes | 5471450 | 2015-09-30 10:08:45 -0700 | [diff] [blame] | 2208 | * If we aren't pid-namespaced, or the jailed program asked to be init: |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2209 | * calling process |
| 2210 | * -> execve()-ing process |
| 2211 | * If we are: |
| 2212 | * calling process |
| 2213 | * -> init()-ing process |
| 2214 | * -> execve()-ing process |
| 2215 | */ |
Jorge Lucangeli Obes | a205390 | 2016-08-02 12:08:15 -0400 | [diff] [blame] | 2216 | ret = execve(filename, argv, environ); |
| 2217 | if (ret == -1) { |
| 2218 | pwarn("execve(%s) failed", filename); |
| 2219 | } |
| 2220 | _exit(ret); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2221 | } |
| 2222 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 2223 | int API minijail_kill(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2224 | { |
| 2225 | int st; |
| 2226 | if (kill(j->initpid, SIGTERM)) |
| 2227 | return -errno; |
| 2228 | if (waitpid(j->initpid, &st, 0) < 0) |
| 2229 | return -errno; |
| 2230 | return st; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2231 | } |
| 2232 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 2233 | int API minijail_wait(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2234 | { |
| 2235 | int st; |
| 2236 | if (waitpid(j->initpid, &st, 0) < 0) |
| 2237 | return -errno; |
Jorge Lucangeli Obes | 1530b74 | 2012-12-11 14:08:09 -0800 | [diff] [blame] | 2238 | |
Jorge Lucangeli Obes | c2c9bcc | 2012-05-01 09:30:24 -0700 | [diff] [blame] | 2239 | if (!WIFEXITED(st)) { |
Jorge Lucangeli Obes | 18d1eba | 2014-04-18 13:58:20 -0700 | [diff] [blame] | 2240 | int error_status = st; |
| 2241 | if (WIFSIGNALED(st)) { |
| 2242 | int signum = WTERMSIG(st); |
mukesh agrawal | c420a26 | 2013-06-11 17:22:42 -0700 | [diff] [blame] | 2243 | warn("child process %d received signal %d", |
Jorge Lucangeli Obes | 18d1eba | 2014-04-18 13:58:20 -0700 | [diff] [blame] | 2244 | j->initpid, signum); |
| 2245 | /* |
| 2246 | * We return MINIJAIL_ERR_JAIL if the process received |
| 2247 | * SIGSYS, which happens when a syscall is blocked by |
| 2248 | * seccomp filters. |
| 2249 | * If not, we do what bash(1) does: |
| 2250 | * $? = 128 + signum |
| 2251 | */ |
| 2252 | if (signum == SIGSYS) { |
| 2253 | error_status = MINIJAIL_ERR_JAIL; |
| 2254 | } else { |
| 2255 | error_status = 128 + signum; |
| 2256 | } |
| 2257 | } |
| 2258 | return error_status; |
Jorge Lucangeli Obes | c2c9bcc | 2012-05-01 09:30:24 -0700 | [diff] [blame] | 2259 | } |
Jorge Lucangeli Obes | 1530b74 | 2012-12-11 14:08:09 -0800 | [diff] [blame] | 2260 | |
| 2261 | int exit_status = WEXITSTATUS(st); |
| 2262 | if (exit_status != 0) |
mukesh agrawal | c420a26 | 2013-06-11 17:22:42 -0700 | [diff] [blame] | 2263 | info("child process %d exited with status %d", |
| 2264 | j->initpid, exit_status); |
Jorge Lucangeli Obes | 1530b74 | 2012-12-11 14:08:09 -0800 | [diff] [blame] | 2265 | |
| 2266 | return exit_status; |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2267 | } |
| 2268 | |
Will Drewry | 6ac9112 | 2011-10-21 16:38:58 -0500 | [diff] [blame] | 2269 | void API minijail_destroy(struct minijail *j) |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2270 | { |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 2271 | size_t i; |
| 2272 | |
Jorge Lucangeli Obes | 524c040 | 2012-01-17 11:30:23 -0800 | [diff] [blame] | 2273 | if (j->flags.seccomp_filter && j->filter_prog) { |
| 2274 | free(j->filter_prog->filter); |
| 2275 | free(j->filter_prog); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2276 | } |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 2277 | while (j->mounts_head) { |
| 2278 | struct mountpoint *m = j->mounts_head; |
| 2279 | j->mounts_head = j->mounts_head->next; |
Dylan Reid | 81e2397 | 2016-05-18 14:06:35 -0700 | [diff] [blame] | 2280 | free(m->data); |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 2281 | free(m->type); |
| 2282 | free(m->dest); |
| 2283 | free(m->src); |
| 2284 | free(m); |
Elly Jones | 51a5b6c | 2011-10-12 19:09:26 -0400 | [diff] [blame] | 2285 | } |
Dylan Reid | 648b220 | 2015-10-23 00:50:00 -0700 | [diff] [blame] | 2286 | j->mounts_tail = NULL; |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2287 | if (j->user) |
| 2288 | free(j->user); |
Jorge Lucangeli Obes | e81a52f | 2015-12-04 16:05:23 -0800 | [diff] [blame] | 2289 | if (j->suppl_gid_list) |
| 2290 | free(j->suppl_gid_list); |
Will Drewry | bee7ba7 | 2011-10-21 20:47:01 -0500 | [diff] [blame] | 2291 | if (j->chrootdir) |
| 2292 | free(j->chrootdir); |
Jorge Lucangeli Obes | 3b2e6e4 | 2016-08-04 12:26:19 -0400 | [diff] [blame] | 2293 | if (j->pid_file_path) |
| 2294 | free(j->pid_file_path); |
| 2295 | if (j->uidmap) |
| 2296 | free(j->uidmap); |
| 2297 | if (j->gidmap) |
| 2298 | free(j->gidmap); |
Andrew Bresticker | eac2894 | 2015-11-11 16:04:46 -0800 | [diff] [blame] | 2299 | if (j->alt_syscall_table) |
| 2300 | free(j->alt_syscall_table); |
Dylan Reid | 605ce7f | 2016-01-19 19:21:00 -0800 | [diff] [blame] | 2301 | for (i = 0; i < j->cgroup_count; ++i) |
| 2302 | free(j->cgroups[i]); |
Elly Jones | e1749eb | 2011-10-07 13:54:59 -0400 | [diff] [blame] | 2303 | free(j); |
Elly Jones | cd7a904 | 2011-07-22 13:56:51 -0400 | [diff] [blame] | 2304 | } |