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