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