Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 2 | /* |
| 3 | * linux/ipc/namespace.c |
| 4 | * Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc. |
| 5 | */ |
| 6 | |
| 7 | #include <linux/ipc.h> |
| 8 | #include <linux/msg.h> |
| 9 | #include <linux/ipc_namespace.h> |
| 10 | #include <linux/rcupdate.h> |
| 11 | #include <linux/nsproxy.h> |
| 12 | #include <linux/slab.h> |
Ingo Molnar | 5b825c3 | 2017-02-02 17:54:15 +0100 | [diff] [blame] | 13 | #include <linux/cred.h> |
Serge E. Hallyn | 7eafd7c | 2009-04-06 19:01:10 -0700 | [diff] [blame] | 14 | #include <linux/fs.h> |
| 15 | #include <linux/mount.h> |
Serge E. Hallyn | b515498 | 2011-03-23 16:43:23 -0700 | [diff] [blame] | 16 | #include <linux/user_namespace.h> |
David Howells | 0bb80f2 | 2013-04-12 01:50:06 +0100 | [diff] [blame] | 17 | #include <linux/proc_ns.h> |
Ingo Molnar | f719ff9 | 2017-02-06 10:57:33 +0100 | [diff] [blame] | 18 | #include <linux/sched/task.h> |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 19 | |
| 20 | #include "util.h" |
| 21 | |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 22 | static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns) |
| 23 | { |
| 24 | return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES); |
| 25 | } |
| 26 | |
| 27 | static void dec_ipc_namespaces(struct ucounts *ucounts) |
| 28 | { |
| 29 | dec_ucount(ucounts, UCOUNT_IPC_NAMESPACES); |
| 30 | } |
| 31 | |
Eric W. Biederman | bcf58e7 | 2012-07-26 04:02:49 -0700 | [diff] [blame] | 32 | static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, |
Serge E. Hallyn | b0e7759 | 2011-03-23 16:43:24 -0700 | [diff] [blame] | 33 | struct ipc_namespace *old_ns) |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 34 | { |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 35 | struct ipc_namespace *ns; |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 36 | struct ucounts *ucounts; |
Serge E. Hallyn | 7eafd7c | 2009-04-06 19:01:10 -0700 | [diff] [blame] | 37 | int err; |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 38 | |
Eric W. Biederman | df75e77 | 2016-09-22 13:08:36 -0500 | [diff] [blame] | 39 | err = -ENOSPC; |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 40 | ucounts = inc_ipc_namespaces(user_ns); |
| 41 | if (!ucounts) |
| 42 | goto fail; |
| 43 | |
| 44 | err = -ENOMEM; |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 45 | ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); |
| 46 | if (ns == NULL) |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 47 | goto fail_dec; |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 48 | |
Al Viro | 6344c43 | 2014-11-01 00:45:45 -0400 | [diff] [blame] | 49 | err = ns_alloc_inum(&ns->ns); |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 50 | if (err) |
| 51 | goto fail_free; |
Al Viro | 33c4294 | 2014-11-01 02:32:53 -0400 | [diff] [blame] | 52 | ns->ns.ops = &ipcns_operations; |
Eric W. Biederman | 98f842e | 2011-06-15 10:21:48 -0700 | [diff] [blame] | 53 | |
Elena Reshetova | a2e0602 | 2017-09-08 16:17:38 -0700 | [diff] [blame] | 54 | refcount_set(&ns->count, 1); |
Eric W. Biederman | b236017 | 2016-05-31 12:26:41 -0500 | [diff] [blame] | 55 | ns->user_ns = get_user_ns(user_ns); |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 56 | ns->ucounts = ucounts; |
Eric W. Biederman | b236017 | 2016-05-31 12:26:41 -0500 | [diff] [blame] | 57 | |
Guillaume Knispel | 0cfb6ae | 2017-09-08 16:17:55 -0700 | [diff] [blame] | 58 | err = mq_init_ns(ns); |
| 59 | if (err) |
Davidlohr Bueso | eae04d2 | 2018-08-21 22:01:56 -0700 | [diff] [blame^] | 60 | goto fail_put; |
| 61 | |
| 62 | sem_init_ns(ns); |
| 63 | msg_init_ns(ns); |
| 64 | shm_init_ns(ns); |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 65 | |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 66 | return ns; |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 67 | |
| 68 | fail_put: |
| 69 | put_user_ns(ns->user_ns); |
| 70 | ns_free_inum(&ns->ns); |
| 71 | fail_free: |
| 72 | kfree(ns); |
| 73 | fail_dec: |
| 74 | dec_ipc_namespaces(ucounts); |
| 75 | fail: |
| 76 | return ERR_PTR(err); |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 77 | } |
| 78 | |
Serge E. Hallyn | b0e7759 | 2011-03-23 16:43:24 -0700 | [diff] [blame] | 79 | struct ipc_namespace *copy_ipcs(unsigned long flags, |
Eric W. Biederman | bcf58e7 | 2012-07-26 04:02:49 -0700 | [diff] [blame] | 80 | struct user_namespace *user_ns, struct ipc_namespace *ns) |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 81 | { |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 82 | if (!(flags & CLONE_NEWIPC)) |
Alexey Dobriyan | 6442428 | 2009-06-17 16:27:54 -0700 | [diff] [blame] | 83 | return get_ipc_ns(ns); |
Eric W. Biederman | bcf58e7 | 2012-07-26 04:02:49 -0700 | [diff] [blame] | 84 | return create_ipc_ns(user_ns, ns); |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 85 | } |
| 86 | |
Pierre Peiffer | 01b8b07 | 2008-02-08 04:18:57 -0800 | [diff] [blame] | 87 | /* |
| 88 | * free_ipcs - free all ipcs of one type |
| 89 | * @ns: the namespace to remove the ipcs from |
| 90 | * @ids: the table of ipcs to free |
| 91 | * @free: the function called to free each individual ipc |
| 92 | * |
| 93 | * Called for each kind of ipc when an ipc_namespace exits. |
| 94 | */ |
| 95 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, |
| 96 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)) |
| 97 | { |
| 98 | struct kern_ipc_perm *perm; |
| 99 | int next_id; |
| 100 | int total, in_use; |
| 101 | |
Davidlohr Bueso | d9a605e | 2013-09-11 14:26:24 -0700 | [diff] [blame] | 102 | down_write(&ids->rwsem); |
Pierre Peiffer | 01b8b07 | 2008-02-08 04:18:57 -0800 | [diff] [blame] | 103 | |
| 104 | in_use = ids->in_use; |
| 105 | |
| 106 | for (total = 0, next_id = 0; total < in_use; next_id++) { |
| 107 | perm = idr_find(&ids->ipcs_idr, next_id); |
| 108 | if (perm == NULL) |
| 109 | continue; |
Davidlohr Bueso | 32a2750 | 2013-09-11 14:26:29 -0700 | [diff] [blame] | 110 | rcu_read_lock(); |
| 111 | ipc_lock_object(perm); |
Pierre Peiffer | 01b8b07 | 2008-02-08 04:18:57 -0800 | [diff] [blame] | 112 | free(ns, perm); |
| 113 | total++; |
| 114 | } |
Davidlohr Bueso | d9a605e | 2013-09-11 14:26:24 -0700 | [diff] [blame] | 115 | up_write(&ids->rwsem); |
Pierre Peiffer | 01b8b07 | 2008-02-08 04:18:57 -0800 | [diff] [blame] | 116 | } |
| 117 | |
Alexey Dobriyan | b4188de | 2009-06-17 16:27:56 -0700 | [diff] [blame] | 118 | static void free_ipc_ns(struct ipc_namespace *ns) |
| 119 | { |
Alexey Dobriyan | b4188de | 2009-06-17 16:27:56 -0700 | [diff] [blame] | 120 | sem_exit_ns(ns); |
| 121 | msg_exit_ns(ns); |
| 122 | shm_exit_ns(ns); |
Alexey Dobriyan | b4188de | 2009-06-17 16:27:56 -0700 | [diff] [blame] | 123 | |
Eric W. Biederman | aba3566 | 2016-08-08 14:20:23 -0500 | [diff] [blame] | 124 | dec_ipc_namespaces(ns->ucounts); |
Serge E. Hallyn | b515498 | 2011-03-23 16:43:23 -0700 | [diff] [blame] | 125 | put_user_ns(ns->user_ns); |
Al Viro | 6344c43 | 2014-11-01 00:45:45 -0400 | [diff] [blame] | 126 | ns_free_inum(&ns->ns); |
Xiaotian Feng | be4d250 | 2011-03-25 01:57:01 -0700 | [diff] [blame] | 127 | kfree(ns); |
Alexey Dobriyan | b4188de | 2009-06-17 16:27:56 -0700 | [diff] [blame] | 128 | } |
| 129 | |
Serge E. Hallyn | 7eafd7c | 2009-04-06 19:01:10 -0700 | [diff] [blame] | 130 | /* |
| 131 | * put_ipc_ns - drop a reference to an ipc namespace. |
| 132 | * @ns: the namespace to put |
| 133 | * |
| 134 | * If this is the last task in the namespace exiting, and |
| 135 | * it is dropping the refcount to 0, then it can race with |
| 136 | * a task in another ipc namespace but in a mounts namespace |
| 137 | * which has this ipcns's mqueuefs mounted, doing some action |
| 138 | * with one of the mqueuefs files. That can raise the refcount. |
| 139 | * So dropping the refcount, and raising the refcount when |
| 140 | * accessing it through the VFS, are protected with mq_lock. |
| 141 | * |
| 142 | * (Clearly, a task raising the refcount on its own ipc_ns |
| 143 | * needn't take mq_lock since it can't race with the last task |
| 144 | * in the ipcns exiting). |
| 145 | */ |
| 146 | void put_ipc_ns(struct ipc_namespace *ns) |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 147 | { |
Elena Reshetova | a2e0602 | 2017-09-08 16:17:38 -0700 | [diff] [blame] | 148 | if (refcount_dec_and_lock(&ns->count, &mq_lock)) { |
Serge E. Hallyn | 7eafd7c | 2009-04-06 19:01:10 -0700 | [diff] [blame] | 149 | mq_clear_sbinfo(ns); |
| 150 | spin_unlock(&mq_lock); |
| 151 | mq_put_mnt(ns); |
| 152 | free_ipc_ns(ns); |
| 153 | } |
| 154 | } |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 155 | |
Al Viro | 3c04118 | 2014-11-01 00:25:30 -0400 | [diff] [blame] | 156 | static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns) |
| 157 | { |
| 158 | return container_of(ns, struct ipc_namespace, ns); |
| 159 | } |
| 160 | |
Al Viro | 6496452 | 2014-11-01 00:37:32 -0400 | [diff] [blame] | 161 | static struct ns_common *ipcns_get(struct task_struct *task) |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 162 | { |
| 163 | struct ipc_namespace *ns = NULL; |
| 164 | struct nsproxy *nsproxy; |
| 165 | |
Eric W. Biederman | 728dba3 | 2014-02-03 19:13:49 -0800 | [diff] [blame] | 166 | task_lock(task); |
| 167 | nsproxy = task->nsproxy; |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 168 | if (nsproxy) |
| 169 | ns = get_ipc_ns(nsproxy->ipc_ns); |
Eric W. Biederman | 728dba3 | 2014-02-03 19:13:49 -0800 | [diff] [blame] | 170 | task_unlock(task); |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 171 | |
Al Viro | 3c04118 | 2014-11-01 00:25:30 -0400 | [diff] [blame] | 172 | return ns ? &ns->ns : NULL; |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 173 | } |
| 174 | |
Al Viro | 6496452 | 2014-11-01 00:37:32 -0400 | [diff] [blame] | 175 | static void ipcns_put(struct ns_common *ns) |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 176 | { |
Al Viro | 3c04118 | 2014-11-01 00:25:30 -0400 | [diff] [blame] | 177 | return put_ipc_ns(to_ipc_ns(ns)); |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 178 | } |
| 179 | |
Al Viro | 6496452 | 2014-11-01 00:37:32 -0400 | [diff] [blame] | 180 | static int ipcns_install(struct nsproxy *nsproxy, struct ns_common *new) |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 181 | { |
Al Viro | 3c04118 | 2014-11-01 00:25:30 -0400 | [diff] [blame] | 182 | struct ipc_namespace *ns = to_ipc_ns(new); |
Eric W. Biederman | 5e4a084 | 2012-12-14 07:55:36 -0800 | [diff] [blame] | 183 | if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || |
Eric W. Biederman | c7b96ac | 2013-03-20 12:49:49 -0700 | [diff] [blame] | 184 | !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) |
Eric W. Biederman | 142e1d1 | 2012-07-26 01:13:20 -0700 | [diff] [blame] | 185 | return -EPERM; |
| 186 | |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 187 | /* Ditch state from the old ipc namespace */ |
| 188 | exit_sem(current); |
| 189 | put_ipc_ns(nsproxy->ipc_ns); |
| 190 | nsproxy->ipc_ns = get_ipc_ns(ns); |
| 191 | return 0; |
| 192 | } |
| 193 | |
Andrey Vagin | bcac25a | 2016-09-06 00:47:13 -0700 | [diff] [blame] | 194 | static struct user_namespace *ipcns_owner(struct ns_common *ns) |
| 195 | { |
| 196 | return to_ipc_ns(ns)->user_ns; |
| 197 | } |
| 198 | |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 199 | const struct proc_ns_operations ipcns_operations = { |
| 200 | .name = "ipc", |
| 201 | .type = CLONE_NEWIPC, |
| 202 | .get = ipcns_get, |
| 203 | .put = ipcns_put, |
| 204 | .install = ipcns_install, |
Andrey Vagin | bcac25a | 2016-09-06 00:47:13 -0700 | [diff] [blame] | 205 | .owner = ipcns_owner, |
Eric W. Biederman | a00eaf1 | 2010-03-07 18:48:39 -0800 | [diff] [blame] | 206 | }; |