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