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 struct user_namespace { 61 struct uid_gid_map uid_map; 62 struct uid_gid_map gid_map; 63 struct uid_gid_map projid_map; 64 struct user_namespace *parent; 65 int level; 66 kuid_t owner; 67 kgid_t group; 68 struct ns_common ns; 69 unsigned long flags; 70 71 #ifdef CONFIG_KEYS 72 /* List of joinable keyrings in this namespace. Modification access of 73 * these pointers is controlled by keyring_sem. Once 74 * user_keyring_register is set, it won't be changed, so it can be 75 * accessed directly with READ_ONCE(). 76 */ 77 struct list_head keyring_name_list; 78 struct key *user_keyring_register; 79 struct rw_semaphore keyring_sem; 80 #endif 81 82 /* Register of per-UID persistent keyrings for this namespace */ 83 #ifdef CONFIG_PERSISTENT_KEYRINGS 84 struct key *persistent_keyring_register; 85 #endif 86 struct work_struct work; 87 #ifdef CONFIG_SYSCTL 88 struct ctl_table_set set; 89 struct ctl_table_header *sysctls; 90 #endif 91 struct ucounts *ucounts; 92 int ucount_max[UCOUNT_COUNTS]; 93 } __randomize_layout; 94 95 struct ucounts { 96 struct hlist_node node; 97 struct user_namespace *ns; 98 kuid_t uid; 99 int count; 100 atomic_t ucount[UCOUNT_COUNTS]; 101 }; 102 103 extern struct user_namespace init_user_ns; 104 105 bool setup_userns_sysctls(struct user_namespace *ns); 106 void retire_userns_sysctls(struct user_namespace *ns); 107 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 108 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 109 110 #ifdef CONFIG_USER_NS 111 112 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 113 { 114 if (ns) 115 refcount_inc(&ns->ns.count); 116 return ns; 117 } 118 119 extern int create_user_ns(struct cred *new); 120 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 121 extern void __put_user_ns(struct user_namespace *ns); 122 123 static inline void put_user_ns(struct user_namespace *ns) 124 { 125 if (ns && refcount_dec_and_test(&ns->ns.count)) 126 __put_user_ns(ns); 127 } 128 129 struct seq_operations; 130 extern const struct seq_operations proc_uid_seq_operations; 131 extern const struct seq_operations proc_gid_seq_operations; 132 extern const struct seq_operations proc_projid_seq_operations; 133 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 134 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 135 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 136 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 137 extern int proc_setgroups_show(struct seq_file *m, void *v); 138 extern bool userns_may_setgroups(const struct user_namespace *ns); 139 extern bool in_userns(const struct user_namespace *ancestor, 140 const struct user_namespace *child); 141 extern bool current_in_userns(const struct user_namespace *target_ns); 142 struct ns_common *ns_get_owner(struct ns_common *ns); 143 #else 144 145 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 146 { 147 return &init_user_ns; 148 } 149 150 static inline int create_user_ns(struct cred *new) 151 { 152 return -EINVAL; 153 } 154 155 static inline int unshare_userns(unsigned long unshare_flags, 156 struct cred **new_cred) 157 { 158 if (unshare_flags & CLONE_NEWUSER) 159 return -EINVAL; 160 return 0; 161 } 162 163 static inline void put_user_ns(struct user_namespace *ns) 164 { 165 } 166 167 static inline bool userns_may_setgroups(const struct user_namespace *ns) 168 { 169 return true; 170 } 171 172 static inline bool in_userns(const struct user_namespace *ancestor, 173 const struct user_namespace *child) 174 { 175 return true; 176 } 177 178 static inline bool current_in_userns(const struct user_namespace *target_ns) 179 { 180 return true; 181 } 182 183 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 184 { 185 return ERR_PTR(-EPERM); 186 } 187 #endif 188 189 #endif /* _LINUX_USER_H */ 190