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 long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type); 131 void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum ucount_type type); 132 bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max); 133 134 static inline void set_rlimit_ucount_max(struct user_namespace *ns, 135 enum ucount_type type, unsigned long max) 136 { 137 ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX; 138 } 139 140 #ifdef CONFIG_USER_NS 141 142 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 143 { 144 if (ns) 145 refcount_inc(&ns->ns.count); 146 return ns; 147 } 148 149 extern int create_user_ns(struct cred *new); 150 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 151 extern void __put_user_ns(struct user_namespace *ns); 152 153 static inline void put_user_ns(struct user_namespace *ns) 154 { 155 if (ns && refcount_dec_and_test(&ns->ns.count)) 156 __put_user_ns(ns); 157 } 158 159 struct seq_operations; 160 extern const struct seq_operations proc_uid_seq_operations; 161 extern const struct seq_operations proc_gid_seq_operations; 162 extern const struct seq_operations proc_projid_seq_operations; 163 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 164 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 165 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 166 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 167 extern int proc_setgroups_show(struct seq_file *m, void *v); 168 extern bool userns_may_setgroups(const struct user_namespace *ns); 169 extern bool in_userns(const struct user_namespace *ancestor, 170 const struct user_namespace *child); 171 extern bool current_in_userns(const struct user_namespace *target_ns); 172 struct ns_common *ns_get_owner(struct ns_common *ns); 173 #else 174 175 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 176 { 177 return &init_user_ns; 178 } 179 180 static inline int create_user_ns(struct cred *new) 181 { 182 return -EINVAL; 183 } 184 185 static inline int unshare_userns(unsigned long unshare_flags, 186 struct cred **new_cred) 187 { 188 if (unshare_flags & CLONE_NEWUSER) 189 return -EINVAL; 190 return 0; 191 } 192 193 static inline void put_user_ns(struct user_namespace *ns) 194 { 195 } 196 197 static inline bool userns_may_setgroups(const struct user_namespace *ns) 198 { 199 return true; 200 } 201 202 static inline bool in_userns(const struct user_namespace *ancestor, 203 const struct user_namespace *child) 204 { 205 return true; 206 } 207 208 static inline bool current_in_userns(const struct user_namespace *target_ns) 209 { 210 return true; 211 } 212 213 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 214 { 215 return ERR_PTR(-EPERM); 216 } 217 #endif 218 219 #endif /* _LINUX_USER_H */ 220