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/rculist_nulls.h> 9 #include <linux/sched.h> 10 #include <linux/workqueue.h> 11 #include <linux/rcuref.h> 12 #include <linux/rwsem.h> 13 #include <linux/sysctl.h> 14 #include <linux/err.h> 15 16 #define UID_GID_MAP_MAX_BASE_EXTENTS 5 17 #define UID_GID_MAP_MAX_EXTENTS 340 18 19 struct uid_gid_extent { 20 u32 first; 21 u32 lower_first; 22 u32 count; 23 }; 24 25 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 26 union { 27 struct { 28 struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS]; 29 u32 nr_extents; 30 }; 31 struct { 32 struct uid_gid_extent *forward; 33 struct uid_gid_extent *reverse; 34 }; 35 }; 36 }; 37 38 #define USERNS_SETGROUPS_ALLOWED 1UL 39 40 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED 41 42 struct ucounts; 43 44 enum ucount_type { 45 UCOUNT_USER_NAMESPACES, 46 UCOUNT_PID_NAMESPACES, 47 UCOUNT_UTS_NAMESPACES, 48 UCOUNT_IPC_NAMESPACES, 49 UCOUNT_NET_NAMESPACES, 50 UCOUNT_MNT_NAMESPACES, 51 UCOUNT_CGROUP_NAMESPACES, 52 UCOUNT_TIME_NAMESPACES, 53 #ifdef CONFIG_INOTIFY_USER 54 UCOUNT_INOTIFY_INSTANCES, 55 UCOUNT_INOTIFY_WATCHES, 56 #endif 57 #ifdef CONFIG_FANOTIFY 58 UCOUNT_FANOTIFY_GROUPS, 59 UCOUNT_FANOTIFY_MARKS, 60 #endif 61 #if IS_ENABLED(CONFIG_BINFMT_MISC) 62 UCOUNT_BINFMT_MISC_INTERPRETERS, 63 #endif 64 UCOUNT_COUNTS, 65 }; 66 67 enum rlimit_type { 68 UCOUNT_RLIMIT_NPROC, 69 UCOUNT_RLIMIT_MSGQUEUE, 70 UCOUNT_RLIMIT_SIGPENDING, 71 UCOUNT_RLIMIT_MEMLOCK, 72 UCOUNT_RLIMIT_COUNTS, 73 }; 74 75 #if IS_ENABLED(CONFIG_BINFMT_MISC) 76 struct binfmt_misc; 77 #endif 78 79 struct user_namespace { 80 struct uid_gid_map uid_map; 81 struct uid_gid_map gid_map; 82 struct uid_gid_map projid_map; 83 struct user_namespace *parent; 84 int level; 85 kuid_t owner; 86 kgid_t group; 87 struct ns_common ns; 88 unsigned long flags; 89 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP 90 * in its effective capability set at the child ns creation time. */ 91 bool parent_could_setfcap; 92 93 #ifdef CONFIG_KEYS 94 /* List of joinable keyrings in this namespace. Modification access of 95 * these pointers is controlled by keyring_sem. Once 96 * user_keyring_register is set, it won't be changed, so it can be 97 * accessed directly with READ_ONCE(). 98 */ 99 struct list_head keyring_name_list; 100 struct key *user_keyring_register; 101 struct rw_semaphore keyring_sem; 102 #endif 103 104 /* Register of per-UID persistent keyrings for this namespace */ 105 #ifdef CONFIG_PERSISTENT_KEYRINGS 106 struct key *persistent_keyring_register; 107 #endif 108 struct work_struct work; 109 #ifdef CONFIG_SYSCTL 110 struct ctl_table_set set; 111 struct ctl_table_header *sysctls; 112 #endif 113 struct ucounts *ucounts; 114 long ucount_max[UCOUNT_COUNTS]; 115 long rlimit_max[UCOUNT_RLIMIT_COUNTS]; 116 117 #if IS_ENABLED(CONFIG_BINFMT_MISC) 118 struct binfmt_misc *binfmt_misc; 119 #endif 120 } __randomize_layout; 121 122 struct ucounts { 123 struct hlist_nulls_node node; 124 struct user_namespace *ns; 125 kuid_t uid; 126 struct rcu_head rcu; 127 rcuref_t count; 128 atomic_long_t ucount[UCOUNT_COUNTS]; 129 atomic_long_t rlimit[UCOUNT_RLIMIT_COUNTS]; 130 }; 131 132 extern struct user_namespace init_user_ns; 133 extern struct ucounts init_ucounts; 134 135 bool setup_userns_sysctls(struct user_namespace *ns); 136 void retire_userns_sysctls(struct user_namespace *ns); 137 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 138 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 139 struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid); 140 void put_ucounts(struct ucounts *ucounts); 141 142 static inline struct ucounts * __must_check get_ucounts(struct ucounts *ucounts) 143 { 144 if (rcuref_get(&ucounts->count)) 145 return ucounts; 146 return NULL; 147 } 148 149 static inline long get_rlimit_value(struct ucounts *ucounts, enum rlimit_type type) 150 { 151 return atomic_long_read(&ucounts->rlimit[type]); 152 } 153 154 long inc_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v); 155 bool dec_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v); 156 long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum rlimit_type type, 157 bool override_rlimit); 158 void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum rlimit_type type); 159 bool is_rlimit_overlimit(struct ucounts *ucounts, enum rlimit_type type, unsigned long max); 160 161 static inline long get_userns_rlimit_max(struct user_namespace *ns, enum rlimit_type type) 162 { 163 return READ_ONCE(ns->rlimit_max[type]); 164 } 165 166 static inline void set_userns_rlimit_max(struct user_namespace *ns, 167 enum rlimit_type type, unsigned long max) 168 { 169 ns->rlimit_max[type] = max <= LONG_MAX ? max : LONG_MAX; 170 } 171 172 static inline struct user_namespace *to_user_ns(struct ns_common *ns) 173 { 174 return container_of(ns, struct user_namespace, ns); 175 } 176 177 #ifdef CONFIG_USER_NS 178 179 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 180 { 181 if (ns) 182 ns_ref_inc(ns); 183 return ns; 184 } 185 186 extern int create_user_ns(struct cred *new); 187 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 188 extern void __put_user_ns(struct user_namespace *ns); 189 190 static inline void put_user_ns(struct user_namespace *ns) 191 { 192 if (ns && ns_ref_put(ns)) 193 __put_user_ns(ns); 194 } 195 196 struct seq_operations; 197 extern const struct seq_operations proc_uid_seq_operations; 198 extern const struct seq_operations proc_gid_seq_operations; 199 extern const struct seq_operations proc_projid_seq_operations; 200 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 201 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 202 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 203 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 204 extern int proc_setgroups_show(struct seq_file *m, void *v); 205 extern bool userns_may_setgroups(const struct user_namespace *ns); 206 extern bool in_userns(const struct user_namespace *ancestor, 207 const struct user_namespace *child); 208 extern bool current_in_userns(const struct user_namespace *target_ns); 209 struct ns_common *ns_get_owner(struct ns_common *ns); 210 #else 211 212 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 213 { 214 return &init_user_ns; 215 } 216 217 static inline int create_user_ns(struct cred *new) 218 { 219 return -EINVAL; 220 } 221 222 static inline int unshare_userns(unsigned long unshare_flags, 223 struct cred **new_cred) 224 { 225 if (unshare_flags & CLONE_NEWUSER) 226 return -EINVAL; 227 return 0; 228 } 229 230 static inline void put_user_ns(struct user_namespace *ns) 231 { 232 } 233 234 static inline bool userns_may_setgroups(const struct user_namespace *ns) 235 { 236 return true; 237 } 238 239 static inline bool in_userns(const struct user_namespace *ancestor, 240 const struct user_namespace *child) 241 { 242 return true; 243 } 244 245 static inline bool current_in_userns(const struct user_namespace *target_ns) 246 { 247 return true; 248 } 249 250 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 251 { 252 return ERR_PTR(-EPERM); 253 } 254 #endif 255 256 #endif /* _LINUX_USER_H */ 257