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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
bdc8e5f8 SH |
2 | /* |
3 | * Copyright (C) 2007 IBM Corporation | |
4 | * | |
5 | * Author: Cedric Le Goater <clg@fr.ibm.com> | |
bdc8e5f8 SH |
6 | */ |
7 | ||
8 | #include <linux/nsproxy.h> | |
9 | #include <linux/ipc_namespace.h> | |
10 | #include <linux/sysctl.h> | |
11 | ||
dc55e35f AG |
12 | #include <linux/stat.h> |
13 | #include <linux/capability.h> | |
14 | #include <linux/slab.h> | |
f9436a5d | 15 | #include <linux/cred.h> |
bdc8e5f8 SH |
16 | |
17 | static int msg_max_limit_min = MIN_MSGMAX; | |
93e6f119 | 18 | static int msg_max_limit_max = HARD_MSGMAX; |
bdc8e5f8 SH |
19 | |
20 | static int msg_maxsize_limit_min = MIN_MSGSIZEMAX; | |
93e6f119 | 21 | static int msg_maxsize_limit_max = HARD_MSGSIZEMAX; |
bdc8e5f8 | 22 | |
a5c5928b | 23 | static struct ctl_table mq_sysctls[] = { |
bdc8e5f8 SH |
24 | { |
25 | .procname = "queues_max", | |
26 | .data = &init_ipc_ns.mq_queues_max, | |
27 | .maxlen = sizeof(int), | |
28 | .mode = 0644, | |
dc55e35f | 29 | .proc_handler = proc_dointvec, |
bdc8e5f8 SH |
30 | }, |
31 | { | |
32 | .procname = "msg_max", | |
33 | .data = &init_ipc_ns.mq_msg_max, | |
34 | .maxlen = sizeof(int), | |
35 | .mode = 0644, | |
dc55e35f | 36 | .proc_handler = proc_dointvec_minmax, |
bdc8e5f8 SH |
37 | .extra1 = &msg_max_limit_min, |
38 | .extra2 = &msg_max_limit_max, | |
39 | }, | |
40 | { | |
41 | .procname = "msgsize_max", | |
42 | .data = &init_ipc_ns.mq_msgsize_max, | |
43 | .maxlen = sizeof(int), | |
44 | .mode = 0644, | |
dc55e35f | 45 | .proc_handler = proc_dointvec_minmax, |
bdc8e5f8 SH |
46 | .extra1 = &msg_maxsize_limit_min, |
47 | .extra2 = &msg_maxsize_limit_max, | |
48 | }, | |
cef0184c KM |
49 | { |
50 | .procname = "msg_default", | |
51 | .data = &init_ipc_ns.mq_msg_default, | |
52 | .maxlen = sizeof(int), | |
53 | .mode = 0644, | |
dc55e35f | 54 | .proc_handler = proc_dointvec_minmax, |
cef0184c KM |
55 | .extra1 = &msg_max_limit_min, |
56 | .extra2 = &msg_max_limit_max, | |
57 | }, | |
58 | { | |
59 | .procname = "msgsize_default", | |
60 | .data = &init_ipc_ns.mq_msgsize_default, | |
61 | .maxlen = sizeof(int), | |
62 | .mode = 0644, | |
dc55e35f | 63 | .proc_handler = proc_dointvec_minmax, |
cef0184c KM |
64 | .extra1 = &msg_maxsize_limit_min, |
65 | .extra2 = &msg_maxsize_limit_max, | |
66 | }, | |
2bc4657c | 67 | {} |
bdc8e5f8 SH |
68 | }; |
69 | ||
dc55e35f AG |
70 | static struct ctl_table_set *set_lookup(struct ctl_table_root *root) |
71 | { | |
72 | return ¤t->nsproxy->ipc_ns->mq_set; | |
73 | } | |
bdc8e5f8 | 74 | |
dc55e35f AG |
75 | static int set_is_seen(struct ctl_table_set *set) |
76 | { | |
77 | return ¤t->nsproxy->ipc_ns->mq_set == set; | |
78 | } | |
79 | ||
f9436a5d | 80 | static void mq_set_ownership(struct ctl_table_header *head, |
f9436a5d AG |
81 | kuid_t *uid, kgid_t *gid) |
82 | { | |
83 | struct ipc_namespace *ns = | |
84 | container_of(head->set, struct ipc_namespace, mq_set); | |
85 | ||
86 | kuid_t ns_root_uid = make_kuid(ns->user_ns, 0); | |
87 | kgid_t ns_root_gid = make_kgid(ns->user_ns, 0); | |
88 | ||
89 | *uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID; | |
90 | *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID; | |
91 | } | |
92 | ||
795f90c6 | 93 | static int mq_permissions(struct ctl_table_header *head, const struct ctl_table *table) |
f9436a5d AG |
94 | { |
95 | int mode = table->mode; | |
96 | kuid_t ns_root_uid; | |
97 | kgid_t ns_root_gid; | |
98 | ||
520713a9 | 99 | mq_set_ownership(head, &ns_root_uid, &ns_root_gid); |
f9436a5d AG |
100 | |
101 | if (uid_eq(current_euid(), ns_root_uid)) | |
102 | mode >>= 6; | |
103 | ||
104 | else if (in_egroup_p(ns_root_gid)) | |
105 | mode >>= 3; | |
106 | ||
107 | mode &= 7; | |
108 | ||
109 | return (mode << 6) | (mode << 3) | mode; | |
110 | } | |
111 | ||
dc55e35f AG |
112 | static struct ctl_table_root set_root = { |
113 | .lookup = set_lookup, | |
f9436a5d AG |
114 | .permissions = mq_permissions, |
115 | .set_ownership = mq_set_ownership, | |
bdc8e5f8 SH |
116 | }; |
117 | ||
dc55e35f | 118 | bool setup_mq_sysctls(struct ipc_namespace *ns) |
bdc8e5f8 | 119 | { |
dc55e35f AG |
120 | struct ctl_table *tbl; |
121 | ||
122 | setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen); | |
123 | ||
124 | tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL); | |
125 | if (tbl) { | |
126 | int i; | |
127 | ||
128 | for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) { | |
129 | if (tbl[i].data == &init_ipc_ns.mq_queues_max) | |
130 | tbl[i].data = &ns->mq_queues_max; | |
131 | ||
132 | else if (tbl[i].data == &init_ipc_ns.mq_msg_max) | |
133 | tbl[i].data = &ns->mq_msg_max; | |
134 | ||
135 | else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max) | |
136 | tbl[i].data = &ns->mq_msgsize_max; | |
137 | ||
138 | else if (tbl[i].data == &init_ipc_ns.mq_msg_default) | |
139 | tbl[i].data = &ns->mq_msg_default; | |
140 | ||
141 | else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default) | |
142 | tbl[i].data = &ns->mq_msgsize_default; | |
143 | else | |
144 | tbl[i].data = NULL; | |
145 | } | |
146 | ||
bff97cf1 JG |
147 | ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, |
148 | "fs/mqueue", tbl, | |
149 | ARRAY_SIZE(mq_sysctls)); | |
dc55e35f AG |
150 | } |
151 | if (!ns->mq_sysctls) { | |
152 | kfree(tbl); | |
153 | retire_sysctl_set(&ns->mq_set); | |
154 | return false; | |
155 | } | |
156 | ||
157 | return true; | |
158 | } | |
159 | ||
160 | void retire_mq_sysctls(struct ipc_namespace *ns) | |
161 | { | |
bfa858f2 | 162 | const struct ctl_table *tbl; |
dc55e35f AG |
163 | |
164 | tbl = ns->mq_sysctls->ctl_table_arg; | |
165 | unregister_sysctl_table(ns->mq_sysctls); | |
166 | retire_sysctl_set(&ns->mq_set); | |
167 | kfree(tbl); | |
bdc8e5f8 | 168 | } |