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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ab516013 SH |
2 | /* |
3 | * Copyright (C) 2006 IBM Corporation | |
4 | * | |
5 | * Author: Serge Hallyn <serue@us.ibm.com> | |
6 | * | |
25b21cb2 KK |
7 | * Jun 2006 - namespaces support |
8 | * OpenVZ, SWsoft Inc. | |
9 | * Pavel Emelianov <xemul@openvz.org> | |
ab516013 SH |
10 | */ |
11 | ||
5a0e3ad6 | 12 | #include <linux/slab.h> |
9984de1a | 13 | #include <linux/export.h> |
ab516013 | 14 | #include <linux/nsproxy.h> |
0437eb59 | 15 | #include <linux/init_task.h> |
6b3286ed | 16 | #include <linux/mnt_namespace.h> |
4865ecf1 | 17 | #include <linux/utsname.h> |
9a575a92 | 18 | #include <linux/pid_namespace.h> |
9dd776b6 | 19 | #include <net/net_namespace.h> |
ae5e1b22 | 20 | #include <linux/ipc_namespace.h> |
769071ac | 21 | #include <linux/time_namespace.h> |
0bb80f24 | 22 | #include <linux/proc_ns.h> |
0663c6f8 EB |
23 | #include <linux/file.h> |
24 | #include <linux/syscalls.h> | |
a79a908f | 25 | #include <linux/cgroup.h> |
e4222673 | 26 | #include <linux/perf_event.h> |
0437eb59 | 27 | |
98c0d07c CLG |
28 | static struct kmem_cache *nsproxy_cachep; |
29 | ||
8467005d | 30 | struct nsproxy init_nsproxy = { |
c2b1df2e AL |
31 | .count = ATOMIC_INIT(1), |
32 | .uts_ns = &init_uts_ns, | |
8467005d | 33 | #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC) |
c2b1df2e | 34 | .ipc_ns = &init_ipc_ns, |
8467005d | 35 | #endif |
c2b1df2e AL |
36 | .mnt_ns = NULL, |
37 | .pid_ns_for_children = &init_pid_ns, | |
8467005d | 38 | #ifdef CONFIG_NET |
c2b1df2e | 39 | .net_ns = &init_net, |
8467005d | 40 | #endif |
a79a908f AK |
41 | #ifdef CONFIG_CGROUPS |
42 | .cgroup_ns = &init_cgroup_ns, | |
43 | #endif | |
769071ac AV |
44 | #ifdef CONFIG_TIME_NS |
45 | .time_ns = &init_time_ns, | |
46 | .time_ns_for_children = &init_time_ns, | |
47 | #endif | |
8467005d | 48 | }; |
ab516013 | 49 | |
90af90d7 | 50 | static inline struct nsproxy *create_nsproxy(void) |
ab516013 | 51 | { |
90af90d7 | 52 | struct nsproxy *nsproxy; |
ab516013 | 53 | |
90af90d7 AD |
54 | nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); |
55 | if (nsproxy) | |
56 | atomic_set(&nsproxy->count, 1); | |
57 | return nsproxy; | |
ab516013 SH |
58 | } |
59 | ||
60 | /* | |
e3222c4e BP |
61 | * Create new nsproxy and all of its the associated namespaces. |
62 | * Return the newly created nsproxy. Do not attach this to the task, | |
63 | * leave it to the caller to do proper locking and attach it to task. | |
ab516013 | 64 | */ |
213dd266 | 65 | static struct nsproxy *create_new_namespaces(unsigned long flags, |
bcf58e72 EB |
66 | struct task_struct *tsk, struct user_namespace *user_ns, |
67 | struct fs_struct *new_fs) | |
ab516013 | 68 | { |
e3222c4e | 69 | struct nsproxy *new_nsp; |
467e9f4b | 70 | int err; |
ab516013 | 71 | |
90af90d7 | 72 | new_nsp = create_nsproxy(); |
e3222c4e BP |
73 | if (!new_nsp) |
74 | return ERR_PTR(-ENOMEM); | |
1651e14e | 75 | |
bcf58e72 | 76 | new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs); |
467e9f4b CLG |
77 | if (IS_ERR(new_nsp->mnt_ns)) { |
78 | err = PTR_ERR(new_nsp->mnt_ns); | |
e3222c4e | 79 | goto out_ns; |
467e9f4b | 80 | } |
e3222c4e | 81 | |
bcf58e72 | 82 | new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns); |
467e9f4b CLG |
83 | if (IS_ERR(new_nsp->uts_ns)) { |
84 | err = PTR_ERR(new_nsp->uts_ns); | |
e3222c4e | 85 | goto out_uts; |
467e9f4b | 86 | } |
e3222c4e | 87 | |
bcf58e72 | 88 | new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns); |
467e9f4b CLG |
89 | if (IS_ERR(new_nsp->ipc_ns)) { |
90 | err = PTR_ERR(new_nsp->ipc_ns); | |
e3222c4e | 91 | goto out_ipc; |
467e9f4b | 92 | } |
e3222c4e | 93 | |
c2b1df2e AL |
94 | new_nsp->pid_ns_for_children = |
95 | copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children); | |
96 | if (IS_ERR(new_nsp->pid_ns_for_children)) { | |
97 | err = PTR_ERR(new_nsp->pid_ns_for_children); | |
e3222c4e | 98 | goto out_pid; |
467e9f4b | 99 | } |
e3222c4e | 100 | |
a79a908f AK |
101 | new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns, |
102 | tsk->nsproxy->cgroup_ns); | |
103 | if (IS_ERR(new_nsp->cgroup_ns)) { | |
104 | err = PTR_ERR(new_nsp->cgroup_ns); | |
105 | goto out_cgroup; | |
106 | } | |
107 | ||
bcf58e72 | 108 | new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns); |
9dd776b6 EB |
109 | if (IS_ERR(new_nsp->net_ns)) { |
110 | err = PTR_ERR(new_nsp->net_ns); | |
111 | goto out_net; | |
112 | } | |
113 | ||
769071ac AV |
114 | new_nsp->time_ns_for_children = copy_time_ns(flags, user_ns, |
115 | tsk->nsproxy->time_ns_for_children); | |
116 | if (IS_ERR(new_nsp->time_ns_for_children)) { | |
117 | err = PTR_ERR(new_nsp->time_ns_for_children); | |
118 | goto out_time; | |
119 | } | |
120 | new_nsp->time_ns = get_time_ns(tsk->nsproxy->time_ns); | |
121 | ||
e3222c4e BP |
122 | return new_nsp; |
123 | ||
769071ac AV |
124 | out_time: |
125 | put_net(new_nsp->net_ns); | |
9dd776b6 | 126 | out_net: |
a79a908f AK |
127 | put_cgroup_ns(new_nsp->cgroup_ns); |
128 | out_cgroup: | |
c2b1df2e AL |
129 | if (new_nsp->pid_ns_for_children) |
130 | put_pid_ns(new_nsp->pid_ns_for_children); | |
e3222c4e BP |
131 | out_pid: |
132 | if (new_nsp->ipc_ns) | |
133 | put_ipc_ns(new_nsp->ipc_ns); | |
134 | out_ipc: | |
135 | if (new_nsp->uts_ns) | |
136 | put_uts_ns(new_nsp->uts_ns); | |
137 | out_uts: | |
138 | if (new_nsp->mnt_ns) | |
139 | put_mnt_ns(new_nsp->mnt_ns); | |
140 | out_ns: | |
98c0d07c | 141 | kmem_cache_free(nsproxy_cachep, new_nsp); |
467e9f4b | 142 | return ERR_PTR(err); |
ab516013 SH |
143 | } |
144 | ||
145 | /* | |
146 | * called from clone. This now handles copy for nsproxy and all | |
147 | * namespaces therein. | |
148 | */ | |
213dd266 | 149 | int copy_namespaces(unsigned long flags, struct task_struct *tsk) |
ab516013 SH |
150 | { |
151 | struct nsproxy *old_ns = tsk->nsproxy; | |
b33c77ef | 152 | struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns); |
1651e14e | 153 | struct nsproxy *new_ns; |
769071ac | 154 | int ret; |
ab516013 | 155 | |
dbef0c1c | 156 | if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | |
a79a908f | 157 | CLONE_NEWPID | CLONE_NEWNET | |
769071ac AV |
158 | CLONE_NEWCGROUP | CLONE_NEWTIME)))) { |
159 | if (likely(old_ns->time_ns_for_children == old_ns->time_ns)) { | |
160 | get_nsproxy(old_ns); | |
161 | return 0; | |
162 | } | |
163 | } else if (!ns_capable(user_ns, CAP_SYS_ADMIN)) | |
dbef0c1c EB |
164 | return -EPERM; |
165 | ||
02fdb36a SH |
166 | /* |
167 | * CLONE_NEWIPC must detach from the undolist: after switching | |
168 | * to a new ipc namespace, the semaphore arrays from the old | |
169 | * namespace are unreachable. In clone parlance, CLONE_SYSVSEM | |
170 | * means share undolist with parent, so we must forbid using | |
171 | * it along with CLONE_NEWIPC. | |
172 | */ | |
21e85194 | 173 | if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) == |
dbef0c1c EB |
174 | (CLONE_NEWIPC | CLONE_SYSVSEM)) |
175 | return -EINVAL; | |
02fdb36a | 176 | |
d7d48f62 | 177 | new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs); |
dbef0c1c EB |
178 | if (IS_ERR(new_ns)) |
179 | return PTR_ERR(new_ns); | |
9a575a92 | 180 | |
769071ac AV |
181 | ret = timens_on_fork(new_ns, tsk); |
182 | if (ret) { | |
183 | free_nsproxy(new_ns); | |
184 | return ret; | |
185 | } | |
186 | ||
e3222c4e | 187 | tsk->nsproxy = new_ns; |
dbef0c1c | 188 | return 0; |
ab516013 SH |
189 | } |
190 | ||
191 | void free_nsproxy(struct nsproxy *ns) | |
192 | { | |
9a575a92 CLG |
193 | if (ns->mnt_ns) |
194 | put_mnt_ns(ns->mnt_ns); | |
195 | if (ns->uts_ns) | |
196 | put_uts_ns(ns->uts_ns); | |
197 | if (ns->ipc_ns) | |
198 | put_ipc_ns(ns->ipc_ns); | |
c2b1df2e AL |
199 | if (ns->pid_ns_for_children) |
200 | put_pid_ns(ns->pid_ns_for_children); | |
769071ac AV |
201 | if (ns->time_ns) |
202 | put_time_ns(ns->time_ns); | |
203 | if (ns->time_ns_for_children) | |
204 | put_time_ns(ns->time_ns_for_children); | |
a79a908f | 205 | put_cgroup_ns(ns->cgroup_ns); |
9dd776b6 | 206 | put_net(ns->net_ns); |
98c0d07c | 207 | kmem_cache_free(nsproxy_cachep, ns); |
ab516013 | 208 | } |
e3222c4e BP |
209 | |
210 | /* | |
211 | * Called from unshare. Unshare all the namespaces part of nsproxy. | |
4e71e474 | 212 | * On success, returns the new nsproxy. |
e3222c4e BP |
213 | */ |
214 | int unshare_nsproxy_namespaces(unsigned long unshare_flags, | |
b2e0d987 | 215 | struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs) |
e3222c4e | 216 | { |
bcf58e72 | 217 | struct user_namespace *user_ns; |
e3222c4e BP |
218 | int err = 0; |
219 | ||
77ec739d | 220 | if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | |
769071ac AV |
221 | CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP | |
222 | CLONE_NEWTIME))) | |
e3222c4e BP |
223 | return 0; |
224 | ||
b2e0d987 EB |
225 | user_ns = new_cred ? new_cred->user_ns : current_user_ns(); |
226 | if (!ns_capable(user_ns, CAP_SYS_ADMIN)) | |
e3222c4e BP |
227 | return -EPERM; |
228 | ||
bcf58e72 | 229 | *new_nsp = create_new_namespaces(unshare_flags, current, user_ns, |
b2e0d987 | 230 | new_fs ? new_fs : current->fs); |
858d72ea | 231 | if (IS_ERR(*new_nsp)) { |
e3222c4e | 232 | err = PTR_ERR(*new_nsp); |
858d72ea SH |
233 | goto out; |
234 | } | |
235 | ||
858d72ea | 236 | out: |
e3222c4e BP |
237 | return err; |
238 | } | |
98c0d07c | 239 | |
cf7b708c PE |
240 | void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) |
241 | { | |
242 | struct nsproxy *ns; | |
243 | ||
244 | might_sleep(); | |
245 | ||
728dba3a | 246 | task_lock(p); |
cf7b708c | 247 | ns = p->nsproxy; |
728dba3a EB |
248 | p->nsproxy = new; |
249 | task_unlock(p); | |
cf7b708c | 250 | |
728dba3a | 251 | if (ns && atomic_dec_and_test(&ns->count)) |
cf7b708c | 252 | free_nsproxy(ns); |
cf7b708c PE |
253 | } |
254 | ||
255 | void exit_task_namespaces(struct task_struct *p) | |
256 | { | |
257 | switch_task_namespaces(p, NULL); | |
258 | } | |
259 | ||
0663c6f8 EB |
260 | SYSCALL_DEFINE2(setns, int, fd, int, nstype) |
261 | { | |
0663c6f8 EB |
262 | struct task_struct *tsk = current; |
263 | struct nsproxy *new_nsproxy; | |
0663c6f8 | 264 | struct file *file; |
33c42940 | 265 | struct ns_common *ns; |
0663c6f8 EB |
266 | int err; |
267 | ||
0663c6f8 EB |
268 | file = proc_ns_fget(fd); |
269 | if (IS_ERR(file)) | |
270 | return PTR_ERR(file); | |
271 | ||
272 | err = -EINVAL; | |
f77c8014 | 273 | ns = get_proc_ns(file_inode(file)); |
33c42940 | 274 | if (nstype && (ns->ops->type != nstype)) |
0663c6f8 EB |
275 | goto out; |
276 | ||
bcf58e72 | 277 | new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs); |
0663c6f8 EB |
278 | if (IS_ERR(new_nsproxy)) { |
279 | err = PTR_ERR(new_nsproxy); | |
280 | goto out; | |
281 | } | |
282 | ||
33c42940 | 283 | err = ns->ops->install(new_nsproxy, ns); |
0663c6f8 EB |
284 | if (err) { |
285 | free_nsproxy(new_nsproxy); | |
286 | goto out; | |
287 | } | |
288 | switch_task_namespaces(tsk, new_nsproxy); | |
e4222673 HB |
289 | |
290 | perf_event_namespaces(tsk); | |
0663c6f8 EB |
291 | out: |
292 | fput(file); | |
293 | return err; | |
294 | } | |
295 | ||
66577193 | 296 | int __init nsproxy_cache_init(void) |
98c0d07c | 297 | { |
db8906da | 298 | nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); |
98c0d07c CLG |
299 | return 0; |
300 | } |