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 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP 71 * in its effective capability set at the child ns creation time. */ 72 bool parent_could_setfcap; 73 74 #ifdef CONFIG_KEYS 75 /* List of joinable keyrings in this namespace. Modification access of 76 * these pointers is controlled by keyring_sem. Once 77 * user_keyring_register is set, it won't be changed, so it can be 78 * accessed directly with READ_ONCE(). 79 */ 80 struct list_head keyring_name_list; 81 struct key *user_keyring_register; 82 struct rw_semaphore keyring_sem; 83 #endif 84 85 /* Register of per-UID persistent keyrings for this namespace */ 86 #ifdef CONFIG_PERSISTENT_KEYRINGS 87 struct key *persistent_keyring_register; 88 #endif 89 struct work_struct work; 90 #ifdef CONFIG_SYSCTL 91 struct ctl_table_set set; 92 struct ctl_table_header *sysctls; 93 #endif 94 struct ucounts *ucounts; 95 int ucount_max[UCOUNT_COUNTS]; 96 } __randomize_layout; 97 98 struct ucounts { 99 struct hlist_node node; 100 struct user_namespace *ns; 101 kuid_t uid; 102 int count; 103 atomic_t ucount[UCOUNT_COUNTS]; 104 }; 105 106 extern struct user_namespace init_user_ns; 107 108 bool setup_userns_sysctls(struct user_namespace *ns); 109 void retire_userns_sysctls(struct user_namespace *ns); 110 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 111 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 112 113 #ifdef CONFIG_USER_NS 114 115 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 116 { 117 if (ns) 118 refcount_inc(&ns->ns.count); 119 return ns; 120 } 121 122 extern int create_user_ns(struct cred *new); 123 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 124 extern void __put_user_ns(struct user_namespace *ns); 125 126 static inline void put_user_ns(struct user_namespace *ns) 127 { 128 if (ns && refcount_dec_and_test(&ns->ns.count)) 129 __put_user_ns(ns); 130 } 131 132 struct seq_operations; 133 extern const struct seq_operations proc_uid_seq_operations; 134 extern const struct seq_operations proc_gid_seq_operations; 135 extern const struct seq_operations proc_projid_seq_operations; 136 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 137 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 138 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 139 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 140 extern int proc_setgroups_show(struct seq_file *m, void *v); 141 extern bool userns_may_setgroups(const struct user_namespace *ns); 142 extern bool in_userns(const struct user_namespace *ancestor, 143 const struct user_namespace *child); 144 extern bool current_in_userns(const struct user_namespace *target_ns); 145 struct ns_common *ns_get_owner(struct ns_common *ns); 146 #else 147 148 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 149 { 150 return &init_user_ns; 151 } 152 153 static inline int create_user_ns(struct cred *new) 154 { 155 return -EINVAL; 156 } 157 158 static inline int unshare_userns(unsigned long unshare_flags, 159 struct cred **new_cred) 160 { 161 if (unshare_flags & CLONE_NEWUSER) 162 return -EINVAL; 163 return 0; 164 } 165 166 static inline void put_user_ns(struct user_namespace *ns) 167 { 168 } 169 170 static inline bool userns_may_setgroups(const struct user_namespace *ns) 171 { 172 return true; 173 } 174 175 static inline bool in_userns(const struct user_namespace *ancestor, 176 const struct user_namespace *child) 177 { 178 return true; 179 } 180 181 static inline bool current_in_userns(const struct user_namespace *target_ns) 182 { 183 return true; 184 } 185 186 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 187 { 188 return ERR_PTR(-EPERM); 189 } 190 #endif 191 192 #endif /* _LINUX_USER_H */ 193