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