Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_USER_NAMESPACE_H
3#define _LINUX_USER_NAMESPACE_H
4
5#include <linux/kref.h>
6#include <linux/nsproxy.h>
7#include <linux/ns_common.h>
8#include <linux/sched.h>
9#include <linux/workqueue.h>
10#include <linux/rwsem.h>
11#include <linux/sysctl.h>
12#include <linux/err.h>
13
14#define UID_GID_MAP_MAX_BASE_EXTENTS 5
15#define UID_GID_MAP_MAX_EXTENTS 340
16
17struct uid_gid_extent {
18 u32 first;
19 u32 lower_first;
20 u32 count;
21};
22
23struct uid_gid_map { /* 64 bytes -- 1 cache line */
24 union {
25 struct {
26 struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS];
27 u32 nr_extents;
28 };
29 struct {
30 struct uid_gid_extent *forward;
31 struct uid_gid_extent *reverse;
32 };
33 };
34};
35
36#define USERNS_SETGROUPS_ALLOWED 1UL
37
38#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
39
40struct ucounts;
41
42enum ucount_type {
43 UCOUNT_USER_NAMESPACES,
44 UCOUNT_PID_NAMESPACES,
45 UCOUNT_UTS_NAMESPACES,
46 UCOUNT_IPC_NAMESPACES,
47 UCOUNT_NET_NAMESPACES,
48 UCOUNT_MNT_NAMESPACES,
49 UCOUNT_CGROUP_NAMESPACES,
50 UCOUNT_TIME_NAMESPACES,
51#ifdef CONFIG_INOTIFY_USER
52 UCOUNT_INOTIFY_INSTANCES,
53 UCOUNT_INOTIFY_WATCHES,
54#endif
55#ifdef CONFIG_FANOTIFY
56 UCOUNT_FANOTIFY_GROUPS,
57 UCOUNT_FANOTIFY_MARKS,
58#endif
59 UCOUNT_COUNTS,
60};
61
62enum rlimit_type {
63 UCOUNT_RLIMIT_NPROC,
64 UCOUNT_RLIMIT_MSGQUEUE,
65 UCOUNT_RLIMIT_SIGPENDING,
66 UCOUNT_RLIMIT_MEMLOCK,
67 UCOUNT_RLIMIT_COUNTS,
68};
69
70#if IS_ENABLED(CONFIG_BINFMT_MISC)
71struct binfmt_misc;
72#endif
73
74struct user_namespace {
75 struct uid_gid_map uid_map;
76 struct uid_gid_map gid_map;
77 struct uid_gid_map projid_map;
78 struct user_namespace *parent;
79 int level;
80 kuid_t owner;
81 kgid_t group;
82 struct ns_common ns;
83 unsigned long flags;
84 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP
85 * in its effective capability set at the child ns creation time. */
86 bool parent_could_setfcap;
87
88#ifdef CONFIG_KEYS
89 /* List of joinable keyrings in this namespace. Modification access of
90 * these pointers is controlled by keyring_sem. Once
91 * user_keyring_register is set, it won't be changed, so it can be
92 * accessed directly with READ_ONCE().
93 */
94 struct list_head keyring_name_list;
95 struct key *user_keyring_register;
96 struct rw_semaphore keyring_sem;
97#endif
98
99 /* Register of per-UID persistent keyrings for this namespace */
100#ifdef CONFIG_PERSISTENT_KEYRINGS
101 struct key *persistent_keyring_register;
102#endif
103 struct work_struct work;
104#ifdef CONFIG_SYSCTL
105 struct ctl_table_set set;
106 struct ctl_table_header *sysctls;
107#endif
108 struct ucounts *ucounts;
109 long ucount_max[UCOUNT_COUNTS];
110 long rlimit_max[UCOUNT_RLIMIT_COUNTS];
111
112#if IS_ENABLED(CONFIG_BINFMT_MISC)
113 struct binfmt_misc *binfmt_misc;
114#endif
115} __randomize_layout;
116
117struct ucounts {
118 struct hlist_node node;
119 struct user_namespace *ns;
120 kuid_t uid;
121 atomic_t count;
122 atomic_long_t ucount[UCOUNT_COUNTS];
123 atomic_long_t rlimit[UCOUNT_RLIMIT_COUNTS];
124};
125
126extern struct user_namespace init_user_ns;
127extern struct ucounts init_ucounts;
128
129bool setup_userns_sysctls(struct user_namespace *ns);
130void retire_userns_sysctls(struct user_namespace *ns);
131struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
132void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
133struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid);
134struct ucounts * __must_check get_ucounts(struct ucounts *ucounts);
135void put_ucounts(struct ucounts *ucounts);
136
137static inline long get_rlimit_value(struct ucounts *ucounts, enum rlimit_type type)
138{
139 return atomic_long_read(&ucounts->rlimit[type]);
140}
141
142long inc_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v);
143bool dec_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v);
144long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum rlimit_type type,
145 bool override_rlimit);
146void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum rlimit_type type);
147bool is_rlimit_overlimit(struct ucounts *ucounts, enum rlimit_type type, unsigned long max);
148
149static inline long get_userns_rlimit_max(struct user_namespace *ns, enum rlimit_type type)
150{
151 return READ_ONCE(ns->rlimit_max[type]);
152}
153
154static inline void set_userns_rlimit_max(struct user_namespace *ns,
155 enum rlimit_type type, unsigned long max)
156{
157 ns->rlimit_max[type] = max <= LONG_MAX ? max : LONG_MAX;
158}
159
160#ifdef CONFIG_USER_NS
161
162static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
163{
164 if (ns)
165 refcount_inc(&ns->ns.count);
166 return ns;
167}
168
169extern int create_user_ns(struct cred *new);
170extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
171extern void __put_user_ns(struct user_namespace *ns);
172
173static inline void put_user_ns(struct user_namespace *ns)
174{
175 if (ns && refcount_dec_and_test(&ns->ns.count))
176 __put_user_ns(ns);
177}
178
179struct seq_operations;
180extern const struct seq_operations proc_uid_seq_operations;
181extern const struct seq_operations proc_gid_seq_operations;
182extern const struct seq_operations proc_projid_seq_operations;
183extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
184extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
185extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
186extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
187extern int proc_setgroups_show(struct seq_file *m, void *v);
188extern bool userns_may_setgroups(const struct user_namespace *ns);
189extern bool in_userns(const struct user_namespace *ancestor,
190 const struct user_namespace *child);
191extern bool current_in_userns(const struct user_namespace *target_ns);
192struct ns_common *ns_get_owner(struct ns_common *ns);
193#else
194
195static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
196{
197 return &init_user_ns;
198}
199
200static inline int create_user_ns(struct cred *new)
201{
202 return -EINVAL;
203}
204
205static inline int unshare_userns(unsigned long unshare_flags,
206 struct cred **new_cred)
207{
208 if (unshare_flags & CLONE_NEWUSER)
209 return -EINVAL;
210 return 0;
211}
212
213static inline void put_user_ns(struct user_namespace *ns)
214{
215}
216
217static inline bool userns_may_setgroups(const struct user_namespace *ns)
218{
219 return true;
220}
221
222static inline bool in_userns(const struct user_namespace *ancestor,
223 const struct user_namespace *child)
224{
225 return true;
226}
227
228static inline bool current_in_userns(const struct user_namespace *target_ns)
229{
230 return true;
231}
232
233static inline struct ns_common *ns_get_owner(struct ns_common *ns)
234{
235 return ERR_PTR(-EPERM);
236}
237#endif
238
239#endif /* _LINUX_USER_H */