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 UCOUNT_COUNTS, 62 }; 63 64 enum rlimit_type { 65 UCOUNT_RLIMIT_NPROC, 66 UCOUNT_RLIMIT_MSGQUEUE, 67 UCOUNT_RLIMIT_SIGPENDING, 68 UCOUNT_RLIMIT_MEMLOCK, 69 UCOUNT_RLIMIT_COUNTS, 70 }; 71 72 #if IS_ENABLED(CONFIG_BINFMT_MISC) 73 struct binfmt_misc; 74 #endif 75 76 struct user_namespace { 77 struct uid_gid_map uid_map; 78 struct uid_gid_map gid_map; 79 struct uid_gid_map projid_map; 80 struct user_namespace *parent; 81 int level; 82 kuid_t owner; 83 kgid_t group; 84 struct ns_common ns; 85 unsigned long flags; 86 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP 87 * in its effective capability set at the child ns creation time. */ 88 bool parent_could_setfcap; 89 90 #ifdef CONFIG_KEYS 91 /* List of joinable keyrings in this namespace. Modification access of 92 * these pointers is controlled by keyring_sem. Once 93 * user_keyring_register is set, it won't be changed, so it can be 94 * accessed directly with READ_ONCE(). 95 */ 96 struct list_head keyring_name_list; 97 struct key *user_keyring_register; 98 struct rw_semaphore keyring_sem; 99 #endif 100 101 /* Register of per-UID persistent keyrings for this namespace */ 102 #ifdef CONFIG_PERSISTENT_KEYRINGS 103 struct key *persistent_keyring_register; 104 #endif 105 struct work_struct work; 106 #ifdef CONFIG_SYSCTL 107 struct ctl_table_set set; 108 struct ctl_table_header *sysctls; 109 #endif 110 struct ucounts *ucounts; 111 long ucount_max[UCOUNT_COUNTS]; 112 long rlimit_max[UCOUNT_RLIMIT_COUNTS]; 113 114 #if IS_ENABLED(CONFIG_BINFMT_MISC) 115 struct binfmt_misc *binfmt_misc; 116 #endif 117 } __randomize_layout; 118 119 struct ucounts { 120 struct hlist_nulls_node node; 121 struct user_namespace *ns; 122 kuid_t uid; 123 struct rcu_head rcu; 124 rcuref_t count; 125 atomic_long_t ucount[UCOUNT_COUNTS]; 126 atomic_long_t rlimit[UCOUNT_RLIMIT_COUNTS]; 127 }; 128 129 extern struct user_namespace init_user_ns; 130 extern struct ucounts init_ucounts; 131 132 bool setup_userns_sysctls(struct user_namespace *ns); 133 void retire_userns_sysctls(struct user_namespace *ns); 134 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 135 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 136 struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid); 137 void put_ucounts(struct ucounts *ucounts); 138 139 static inline struct ucounts * __must_check get_ucounts(struct ucounts *ucounts) 140 { 141 if (rcuref_get(&ucounts->count)) 142 return ucounts; 143 return NULL; 144 } 145 146 static inline long get_rlimit_value(struct ucounts *ucounts, enum rlimit_type type) 147 { 148 return atomic_long_read(&ucounts->rlimit[type]); 149 } 150 151 long inc_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v); 152 bool dec_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v); 153 long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum rlimit_type type, 154 bool override_rlimit); 155 void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum rlimit_type type); 156 bool is_rlimit_overlimit(struct ucounts *ucounts, enum rlimit_type type, unsigned long max); 157 158 static inline long get_userns_rlimit_max(struct user_namespace *ns, enum rlimit_type type) 159 { 160 return READ_ONCE(ns->rlimit_max[type]); 161 } 162 163 static inline void set_userns_rlimit_max(struct user_namespace *ns, 164 enum rlimit_type type, unsigned long max) 165 { 166 ns->rlimit_max[type] = max <= LONG_MAX ? max : LONG_MAX; 167 } 168 169 #ifdef CONFIG_USER_NS 170 171 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 172 { 173 if (ns) 174 refcount_inc(&ns->ns.count); 175 return ns; 176 } 177 178 extern int create_user_ns(struct cred *new); 179 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 180 extern void __put_user_ns(struct user_namespace *ns); 181 182 static inline void put_user_ns(struct user_namespace *ns) 183 { 184 if (ns && refcount_dec_and_test(&ns->ns.count)) 185 __put_user_ns(ns); 186 } 187 188 struct seq_operations; 189 extern const struct seq_operations proc_uid_seq_operations; 190 extern const struct seq_operations proc_gid_seq_operations; 191 extern const struct seq_operations proc_projid_seq_operations; 192 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 193 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 194 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 195 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 196 extern int proc_setgroups_show(struct seq_file *m, void *v); 197 extern bool userns_may_setgroups(const struct user_namespace *ns); 198 extern bool in_userns(const struct user_namespace *ancestor, 199 const struct user_namespace *child); 200 extern bool current_in_userns(const struct user_namespace *target_ns); 201 struct ns_common *ns_get_owner(struct ns_common *ns); 202 #else 203 204 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 205 { 206 return &init_user_ns; 207 } 208 209 static inline int create_user_ns(struct cred *new) 210 { 211 return -EINVAL; 212 } 213 214 static inline int unshare_userns(unsigned long unshare_flags, 215 struct cred **new_cred) 216 { 217 if (unshare_flags & CLONE_NEWUSER) 218 return -EINVAL; 219 return 0; 220 } 221 222 static inline void put_user_ns(struct user_namespace *ns) 223 { 224 } 225 226 static inline bool userns_may_setgroups(const struct user_namespace *ns) 227 { 228 return true; 229 } 230 231 static inline bool in_userns(const struct user_namespace *ancestor, 232 const struct user_namespace *child) 233 { 234 return true; 235 } 236 237 static inline bool current_in_userns(const struct user_namespace *target_ns) 238 { 239 return true; 240 } 241 242 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 243 { 244 return ERR_PTR(-EPERM); 245 } 246 #endif 247 248 #endif /* _LINUX_USER_H */ 249