]> git.ipfire.org Git - thirdparty/kernel/stable.git/blame - ipc/ipc_sysctl.c
ipc: remove the now superfluous sentinel element from ctl_table array
[thirdparty/kernel/stable.git] / ipc / ipc_sysctl.c
CommitLineData
b886d83c 1// SPDX-License-Identifier: GPL-2.0-only
a5494dcd
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2/*
3 * Copyright (C) 2007
4 *
5 * Author: Eric Biederman <ebiederm@xmision.com>
a5494dcd
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6 */
7
8#include <linux/module.h>
9#include <linux/ipc.h>
10#include <linux/nsproxy.h>
11#include <linux/sysctl.h>
12#include <linux/uaccess.h>
5563cabd 13#include <linux/capability.h>
ae5e1b22 14#include <linux/ipc_namespace.h>
6546bc42 15#include <linux/msg.h>
1f5c135e 16#include <linux/slab.h>
50ec499b 17#include <linux/cred.h>
6546bc42 18#include "util.h"
a5494dcd 19
1f5c135e 20static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
32927393 21 void *buffer, size_t *lenp, loff_t *ppos)
b34a6b1d 22{
dd141a49
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23 struct ipc_namespace *ns =
24 container_of(table->data, struct ipc_namespace, shm_rmid_forced);
1f5c135e 25 int err;
b34a6b1d 26
dd141a49 27 err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
b34a6b1d
VK
28
29 if (err < 0)
30 return err;
31 if (ns->shm_rmid_forced)
32 shm_destroy_orphaned(ns);
33 return err;
34}
35
0050ee05 36static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
32927393 37 void *buffer, size_t *lenp, loff_t *ppos)
9eefe520
ND
38{
39 struct ctl_table ipc_table;
0050ee05 40 int dummy = 0;
9eefe520
ND
41
42 memcpy(&ipc_table, table, sizeof(ipc_table));
0050ee05
MS
43 ipc_table.data = &dummy;
44
45 if (write)
46 pr_info_once("writing to auto_msgmni has no effect");
47
48 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
9eefe520
ND
49}
50
8c81ddd2 51static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
fff1662c 52 void *buffer, size_t *lenp, loff_t *ppos)
8c81ddd2 53{
dd141a49
AG
54 struct ipc_namespace *ns =
55 container_of(table->data, struct ipc_namespace, sem_ctls);
8c81ddd2 56 int ret, semmni;
1f5c135e 57
8c81ddd2 58 semmni = ns->sem_ctls[3];
1f5c135e 59 ret = proc_dointvec(table, write, buffer, lenp, ppos);
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60
61 if (!ret)
def7343f 62 ret = sem_check_semmni(ns);
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63
64 /*
65 * Reset the semmni value if an error happens.
66 */
67 if (ret)
68 ns->sem_ctls[3] = semmni;
69 return ret;
70}
71
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72int ipc_mni = IPCMNI;
73int ipc_mni_shift = IPCMNI_SHIFT;
99db46ea 74int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
9eefe520 75
1f5c135e 76static struct ctl_table ipc_sysctls[] = {
a5494dcd 77 {
a5494dcd
EB
78 .procname = "shmmax",
79 .data = &init_ipc_ns.shm_ctlmax,
239521f3 80 .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
a5494dcd 81 .mode = 0644,
1f5c135e 82 .proc_handler = proc_doulongvec_minmax,
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83 },
84 {
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85 .procname = "shmall",
86 .data = &init_ipc_ns.shm_ctlall,
239521f3 87 .maxlen = sizeof(init_ipc_ns.shm_ctlall),
a5494dcd 88 .mode = 0644,
1f5c135e 89 .proc_handler = proc_doulongvec_minmax,
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90 },
91 {
a5494dcd
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92 .procname = "shmmni",
93 .data = &init_ipc_ns.shm_ctlmni,
239521f3 94 .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
a5494dcd 95 .mode = 0644,
1f5c135e 96 .proc_handler = proc_dointvec_minmax,
eec4844f 97 .extra1 = SYSCTL_ZERO,
6730e658 98 .extra2 = &ipc_mni,
a5494dcd 99 },
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100 {
101 .procname = "shm_rmid_forced",
102 .data = &init_ipc_ns.shm_rmid_forced,
103 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
104 .mode = 0644,
105 .proc_handler = proc_ipc_dointvec_minmax_orphans,
dd141a49
AG
106 .extra1 = SYSCTL_ZERO,
107 .extra2 = SYSCTL_ONE,
b34a6b1d 108 },
a5494dcd 109 {
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110 .procname = "msgmax",
111 .data = &init_ipc_ns.msg_ctlmax,
239521f3 112 .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
a5494dcd 113 .mode = 0644,
1f5c135e 114 .proc_handler = proc_dointvec_minmax,
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115 .extra1 = SYSCTL_ZERO,
116 .extra2 = SYSCTL_INT_MAX,
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117 },
118 {
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119 .procname = "msgmni",
120 .data = &init_ipc_ns.msg_ctlmni,
239521f3 121 .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
a5494dcd 122 .mode = 0644,
1f5c135e 123 .proc_handler = proc_dointvec_minmax,
eec4844f 124 .extra1 = SYSCTL_ZERO,
6730e658 125 .extra2 = &ipc_mni,
a5494dcd 126 },
0050ee05
MS
127 {
128 .procname = "auto_msgmni",
129 .data = NULL,
130 .maxlen = sizeof(int),
131 .mode = 0644,
132 .proc_handler = proc_ipc_auto_msgmni,
eec4844f
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133 .extra1 = SYSCTL_ZERO,
134 .extra2 = SYSCTL_ONE,
0050ee05 135 },
a5494dcd 136 {
a5494dcd
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137 .procname = "msgmnb",
138 .data = &init_ipc_ns.msg_ctlmnb,
239521f3 139 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
a5494dcd 140 .mode = 0644,
1f5c135e 141 .proc_handler = proc_dointvec_minmax,
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142 .extra1 = SYSCTL_ZERO,
143 .extra2 = SYSCTL_INT_MAX,
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144 },
145 {
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146 .procname = "sem",
147 .data = &init_ipc_ns.sem_ctls,
239521f3 148 .maxlen = 4*sizeof(int),
a5494dcd 149 .mode = 0644,
8c81ddd2 150 .proc_handler = proc_ipc_sem_dointvec,
a5494dcd 151 },
03f59566
SK
152#ifdef CONFIG_CHECKPOINT_RESTORE
153 {
154 .procname = "sem_next_id",
155 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
156 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
0889f44e
AG
157 .mode = 0444,
158 .proc_handler = proc_dointvec_minmax,
159 .extra1 = SYSCTL_ZERO,
160 .extra2 = SYSCTL_INT_MAX,
03f59566
SK
161 },
162 {
163 .procname = "msg_next_id",
164 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
165 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
0889f44e
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166 .mode = 0444,
167 .proc_handler = proc_dointvec_minmax,
168 .extra1 = SYSCTL_ZERO,
169 .extra2 = SYSCTL_INT_MAX,
03f59566
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170 },
171 {
172 .procname = "shm_next_id",
173 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
174 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
0889f44e
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175 .mode = 0444,
176 .proc_handler = proc_dointvec_minmax,
177 .extra1 = SYSCTL_ZERO,
178 .extra2 = SYSCTL_INT_MAX,
03f59566
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179 },
180#endif
a5494dcd
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181};
182
1f5c135e
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183static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
184{
185 return &current->nsproxy->ipc_ns->ipc_set;
186}
187
188static int set_is_seen(struct ctl_table_set *set)
189{
190 return &current->nsproxy->ipc_ns->ipc_set == set;
191}
192
50ec499b
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193static void ipc_set_ownership(struct ctl_table_header *head,
194 struct ctl_table *table,
195 kuid_t *uid, kgid_t *gid)
196{
197 struct ipc_namespace *ns =
198 container_of(head->set, struct ipc_namespace, ipc_set);
199
200 kuid_t ns_root_uid = make_kuid(ns->user_ns, 0);
201 kgid_t ns_root_gid = make_kgid(ns->user_ns, 0);
202
203 *uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID;
204 *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID;
205}
206
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207static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table)
208{
209 int mode = table->mode;
210
211#ifdef CONFIG_CHECKPOINT_RESTORE
50ec499b
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212 struct ipc_namespace *ns =
213 container_of(head->set, struct ipc_namespace, ipc_set);
0889f44e
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214
215 if (((table->data == &ns->ids[IPC_SEM_IDS].next_id) ||
216 (table->data == &ns->ids[IPC_MSG_IDS].next_id) ||
217 (table->data == &ns->ids[IPC_SHM_IDS].next_id)) &&
218 checkpoint_restore_ns_capable(ns->user_ns))
219 mode = 0666;
50ec499b 220 else
0889f44e 221#endif
50ec499b
AG
222 {
223 kuid_t ns_root_uid;
224 kgid_t ns_root_gid;
225
226 ipc_set_ownership(head, table, &ns_root_uid, &ns_root_gid);
227
228 if (uid_eq(current_euid(), ns_root_uid))
229 mode >>= 6;
230
231 else if (in_egroup_p(ns_root_gid))
232 mode >>= 3;
233 }
234
235 mode &= 7;
236
237 return (mode << 6) | (mode << 3) | mode;
0889f44e
AG
238}
239
1f5c135e
AG
240static struct ctl_table_root set_root = {
241 .lookup = set_lookup,
0889f44e 242 .permissions = ipc_permissions,
50ec499b 243 .set_ownership = ipc_set_ownership,
a5494dcd
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244};
245
1f5c135e
AG
246bool setup_ipc_sysctls(struct ipc_namespace *ns)
247{
248 struct ctl_table *tbl;
249
250 setup_sysctl_set(&ns->ipc_set, &set_root, set_is_seen);
251
252 tbl = kmemdup(ipc_sysctls, sizeof(ipc_sysctls), GFP_KERNEL);
253 if (tbl) {
254 int i;
255
256 for (i = 0; i < ARRAY_SIZE(ipc_sysctls); i++) {
38cd5b12 257 if (tbl[i].data == &init_ipc_ns.shm_ctlmax)
1f5c135e
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258 tbl[i].data = &ns->shm_ctlmax;
259
38cd5b12 260 else if (tbl[i].data == &init_ipc_ns.shm_ctlall)
1f5c135e
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261 tbl[i].data = &ns->shm_ctlall;
262
38cd5b12 263 else if (tbl[i].data == &init_ipc_ns.shm_ctlmni)
1f5c135e
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264 tbl[i].data = &ns->shm_ctlmni;
265
38cd5b12 266 else if (tbl[i].data == &init_ipc_ns.shm_rmid_forced)
1f5c135e 267 tbl[i].data = &ns->shm_rmid_forced;
1f5c135e 268
38cd5b12 269 else if (tbl[i].data == &init_ipc_ns.msg_ctlmax)
1f5c135e
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270 tbl[i].data = &ns->msg_ctlmax;
271
38cd5b12 272 else if (tbl[i].data == &init_ipc_ns.msg_ctlmni)
1f5c135e
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273 tbl[i].data = &ns->msg_ctlmni;
274
38cd5b12 275 else if (tbl[i].data == &init_ipc_ns.msg_ctlmnb)
1f5c135e
AG
276 tbl[i].data = &ns->msg_ctlmnb;
277
38cd5b12 278 else if (tbl[i].data == &init_ipc_ns.sem_ctls)
1f5c135e 279 tbl[i].data = &ns->sem_ctls;
1f5c135e 280#ifdef CONFIG_CHECKPOINT_RESTORE
38cd5b12 281 else if (tbl[i].data == &init_ipc_ns.ids[IPC_SEM_IDS].next_id)
1f5c135e 282 tbl[i].data = &ns->ids[IPC_SEM_IDS].next_id;
1f5c135e 283
38cd5b12 284 else if (tbl[i].data == &init_ipc_ns.ids[IPC_MSG_IDS].next_id)
1f5c135e 285 tbl[i].data = &ns->ids[IPC_MSG_IDS].next_id;
1f5c135e 286
38cd5b12 287 else if (tbl[i].data == &init_ipc_ns.ids[IPC_SHM_IDS].next_id)
1f5c135e 288 tbl[i].data = &ns->ids[IPC_SHM_IDS].next_id;
1f5c135e 289#endif
38cd5b12 290 else
1f5c135e 291 tbl[i].data = NULL;
1f5c135e
AG
292 }
293
8e882910 294 ns->ipc_sysctls = __register_sysctl_table(&ns->ipc_set, "kernel", tbl,
bff97cf1 295 ARRAY_SIZE(ipc_sysctls));
1f5c135e
AG
296 }
297 if (!ns->ipc_sysctls) {
298 kfree(tbl);
299 retire_sysctl_set(&ns->ipc_set);
300 return false;
301 }
302
303 return true;
304}
305
306void retire_ipc_sysctls(struct ipc_namespace *ns)
307{
308 struct ctl_table *tbl;
309
310 tbl = ns->ipc_sysctls->ctl_table_arg;
311 unregister_sysctl_table(ns->ipc_sysctls);
312 retire_sysctl_set(&ns->ipc_set);
313 kfree(tbl);
314}
315
a5494dcd
EB
316static int __init ipc_sysctl_init(void)
317{
1f5c135e
AG
318 if (!setup_ipc_sysctls(&init_ipc_ns)) {
319 pr_warn("ipc sysctl registration failed\n");
320 return -ENOMEM;
321 }
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EB
322 return 0;
323}
324
6d08a256 325device_initcall(ipc_sysctl_init);
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WL
326
327static int __init ipc_mni_extend(char *str)
328{
329 ipc_mni = IPCMNI_EXTEND;
330 ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
99db46ea 331 ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE;
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WL
332 pr_info("IPCMNI extended to %d.\n", ipc_mni);
333 return 0;
334}
335early_param("ipcmni_extend", ipc_mni_extend);