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 17 struct uid_gid_extent { 18 u32 first; 19 u32 lower_first; 20 u32 count; 21 }; 22 23 struct 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 40 struct ucounts; 41 42 enum 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 62 enum 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) 71 struct binfmt_misc; 72 #endif 73 74 struct 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; 116 117 struct 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 }; 125 126 extern struct user_namespace init_user_ns; 127 extern struct ucounts init_ucounts; 128 129 bool setup_userns_sysctls(struct user_namespace *ns); 130 void retire_userns_sysctls(struct user_namespace *ns); 131 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 132 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 133 struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid); 134 struct ucounts * __must_check get_ucounts(struct ucounts *ucounts); 135 void put_ucounts(struct ucounts *ucounts); 136 137 static inline long get_rlimit_value(struct ucounts *ucounts, enum rlimit_type type) 138 { 139 return atomic_long_read(&ucounts->rlimit[type]); 140 } 141 142 long inc_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v); 143 bool dec_rlimit_ucounts(struct ucounts *ucounts, enum rlimit_type type, long v); 144 long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum rlimit_type type); 145 void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum rlimit_type type); 146 bool is_rlimit_overlimit(struct ucounts *ucounts, enum rlimit_type type, unsigned long max); 147 148 static inline long get_userns_rlimit_max(struct user_namespace *ns, enum rlimit_type type) 149 { 150 return READ_ONCE(ns->rlimit_max[type]); 151 } 152 153 static inline void set_userns_rlimit_max(struct user_namespace *ns, 154 enum rlimit_type type, unsigned long max) 155 { 156 ns->rlimit_max[type] = max <= LONG_MAX ? max : LONG_MAX; 157 } 158 159 #ifdef CONFIG_USER_NS 160 161 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 162 { 163 if (ns) 164 refcount_inc(&ns->ns.count); 165 return ns; 166 } 167 168 extern int create_user_ns(struct cred *new); 169 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 170 extern void __put_user_ns(struct user_namespace *ns); 171 172 static inline void put_user_ns(struct user_namespace *ns) 173 { 174 if (ns && refcount_dec_and_test(&ns->ns.count)) 175 __put_user_ns(ns); 176 } 177 178 struct seq_operations; 179 extern const struct seq_operations proc_uid_seq_operations; 180 extern const struct seq_operations proc_gid_seq_operations; 181 extern const struct seq_operations proc_projid_seq_operations; 182 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 183 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 184 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 185 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 186 extern int proc_setgroups_show(struct seq_file *m, void *v); 187 extern bool userns_may_setgroups(const struct user_namespace *ns); 188 extern bool in_userns(const struct user_namespace *ancestor, 189 const struct user_namespace *child); 190 extern bool current_in_userns(const struct user_namespace *target_ns); 191 struct ns_common *ns_get_owner(struct ns_common *ns); 192 #else 193 194 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 195 { 196 return &init_user_ns; 197 } 198 199 static inline int create_user_ns(struct cred *new) 200 { 201 return -EINVAL; 202 } 203 204 static inline int unshare_userns(unsigned long unshare_flags, 205 struct cred **new_cred) 206 { 207 if (unshare_flags & CLONE_NEWUSER) 208 return -EINVAL; 209 return 0; 210 } 211 212 static inline void put_user_ns(struct user_namespace *ns) 213 { 214 } 215 216 static inline bool userns_may_setgroups(const struct user_namespace *ns) 217 { 218 return true; 219 } 220 221 static inline bool in_userns(const struct user_namespace *ancestor, 222 const struct user_namespace *child) 223 { 224 return true; 225 } 226 227 static inline bool current_in_userns(const struct user_namespace *target_ns) 228 { 229 return true; 230 } 231 232 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 233 { 234 return ERR_PTR(-EPERM); 235 } 236 #endif 237 238 #endif /* _LINUX_USER_H */ 239