1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_USER_NAMESPACE_H
3 #define _LINUX_USER_NAMESPACE_H
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>
14 #define UID_GID_MAP_MAX_BASE_EXTENTS 5
15 #define UID_GID_MAP_MAX_EXTENTS 340
17 struct uid_gid_extent {
23 struct uid_gid_map { /* 64 bytes -- 1 cache line */
26 struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS];
28 struct uid_gid_extent *forward;
29 struct uid_gid_extent *reverse;
34 #define USERNS_SETGROUPS_ALLOWED 1UL
36 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
41 UCOUNT_USER_NAMESPACES,
42 UCOUNT_PID_NAMESPACES,
43 UCOUNT_UTS_NAMESPACES,
44 UCOUNT_IPC_NAMESPACES,
45 UCOUNT_NET_NAMESPACES,
46 UCOUNT_MNT_NAMESPACES,
47 UCOUNT_CGROUP_NAMESPACES,
48 UCOUNT_TIME_NAMESPACES,
49 #ifdef CONFIG_INOTIFY_USER
50 UCOUNT_INOTIFY_INSTANCES,
51 UCOUNT_INOTIFY_WATCHES,
53 #ifdef CONFIG_FANOTIFY
54 UCOUNT_FANOTIFY_GROUPS,
55 UCOUNT_FANOTIFY_MARKS,
58 UCOUNT_RLIMIT_MSGQUEUE,
59 UCOUNT_RLIMIT_SIGPENDING,
60 UCOUNT_RLIMIT_MEMLOCK,
64 #define MAX_PER_NAMESPACE_UCOUNTS UCOUNT_RLIMIT_NPROC
66 struct user_namespace {
67 struct uid_gid_map uid_map;
68 struct uid_gid_map gid_map;
69 struct uid_gid_map projid_map;
70 struct user_namespace *parent;
76 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP
77 * in its effective capability set at the child ns creation time. */
78 bool parent_could_setfcap;
81 /* List of joinable keyrings in this namespace. Modification access of
82 * these pointers is controlled by keyring_sem. Once
83 * user_keyring_register is set, it won't be changed, so it can be
84 * accessed directly with READ_ONCE().
86 struct list_head keyring_name_list;
87 struct key *user_keyring_register;
88 struct rw_semaphore keyring_sem;
91 /* Register of per-UID persistent keyrings for this namespace */
92 #ifdef CONFIG_PERSISTENT_KEYRINGS
93 struct key *persistent_keyring_register;
95 struct work_struct work;
97 struct ctl_table_set set;
98 struct ctl_table_header *sysctls;
100 struct ucounts *ucounts;
101 long ucount_max[UCOUNT_COUNTS];
102 } __randomize_layout;
105 struct hlist_node node;
106 struct user_namespace *ns;
109 atomic_long_t ucount[UCOUNT_COUNTS];
112 extern struct user_namespace init_user_ns;
113 extern struct ucounts init_ucounts;
115 bool setup_userns_sysctls(struct user_namespace *ns);
116 void retire_userns_sysctls(struct user_namespace *ns);
117 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
118 void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
119 struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid);
120 struct ucounts * __must_check get_ucounts(struct ucounts *ucounts);
121 void put_ucounts(struct ucounts *ucounts);
123 static inline long get_ucounts_value(struct ucounts *ucounts, enum ucount_type type)
125 return atomic_long_read(&ucounts->ucount[type]);
128 long inc_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
129 bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
130 long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type);
131 void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum ucount_type type);
132 bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max);
134 static inline void set_rlimit_ucount_max(struct user_namespace *ns,
135 enum ucount_type type, unsigned long max)
137 ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX;
140 #ifdef CONFIG_USER_NS
142 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
145 refcount_inc(&ns->ns.count);
149 extern int create_user_ns(struct cred *new);
150 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
151 extern void __put_user_ns(struct user_namespace *ns);
153 static inline void put_user_ns(struct user_namespace *ns)
155 if (ns && refcount_dec_and_test(&ns->ns.count))
159 struct seq_operations;
160 extern const struct seq_operations proc_uid_seq_operations;
161 extern const struct seq_operations proc_gid_seq_operations;
162 extern const struct seq_operations proc_projid_seq_operations;
163 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
164 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
165 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
166 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
167 extern int proc_setgroups_show(struct seq_file *m, void *v);
168 extern bool userns_may_setgroups(const struct user_namespace *ns);
169 extern bool in_userns(const struct user_namespace *ancestor,
170 const struct user_namespace *child);
171 extern bool current_in_userns(const struct user_namespace *target_ns);
172 struct ns_common *ns_get_owner(struct ns_common *ns);
175 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
177 return &init_user_ns;
180 static inline int create_user_ns(struct cred *new)
185 static inline int unshare_userns(unsigned long unshare_flags,
186 struct cred **new_cred)
188 if (unshare_flags & CLONE_NEWUSER)
193 static inline void put_user_ns(struct user_namespace *ns)
197 static inline bool userns_may_setgroups(const struct user_namespace *ns)
202 static inline bool in_userns(const struct user_namespace *ancestor,
203 const struct user_namespace *child)
208 static inline bool current_in_userns(const struct user_namespace *target_ns)
213 static inline struct ns_common *ns_get_owner(struct ns_common *ns)
215 return ERR_PTR(-EPERM);
219 #endif /* _LINUX_USER_H */