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 #ifdef CONFIG_INOTIFY_USER 49 UCOUNT_INOTIFY_INSTANCES, 50 UCOUNT_INOTIFY_WATCHES, 51 #endif 52 UCOUNT_COUNTS, 53 }; 54 55 struct user_namespace { 56 struct uid_gid_map uid_map; 57 struct uid_gid_map gid_map; 58 struct uid_gid_map projid_map; 59 atomic_t count; 60 struct user_namespace *parent; 61 int level; 62 kuid_t owner; 63 kgid_t group; 64 struct ns_common ns; 65 unsigned long flags; 66 67 #ifdef CONFIG_KEYS 68 /* List of joinable keyrings in this namespace. Modification access of 69 * these pointers is controlled by keyring_sem. Once 70 * user_keyring_register is set, it won't be changed, so it can be 71 * accessed directly with READ_ONCE(). 72 */ 73 struct list_head keyring_name_list; 74 struct key *user_keyring_register; 75 struct rw_semaphore keyring_sem; 76 #endif 77 78 /* Register of per-UID persistent keyrings for this namespace */ 79 #ifdef CONFIG_PERSISTENT_KEYRINGS 80 struct key *persistent_keyring_register; 81 #endif 82 struct work_struct work; 83 #ifdef CONFIG_SYSCTL 84 struct ctl_table_set set; 85 struct ctl_table_header *sysctls; 86 #endif 87 struct ucounts *ucounts; 88 int ucount_max[UCOUNT_COUNTS]; 89 } __randomize_layout; 90 91 struct ucounts { 92 struct hlist_node node; 93 struct user_namespace *ns; 94 kuid_t uid; 95 int count; 96 atomic_t ucount[UCOUNT_COUNTS]; 97 }; 98 99 extern struct user_namespace init_user_ns; 100 101 bool setup_userns_sysctls(struct user_namespace *ns); 102 void retire_userns_sysctls(struct user_namespace *ns); 103 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 104 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 105 106 #ifdef CONFIG_USER_NS 107 108 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 109 { 110 if (ns) 111 atomic_inc(&ns->count); 112 return ns; 113 } 114 115 extern int create_user_ns(struct cred *new); 116 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 117 extern void __put_user_ns(struct user_namespace *ns); 118 119 static inline void put_user_ns(struct user_namespace *ns) 120 { 121 if (ns && atomic_dec_and_test(&ns->count)) 122 __put_user_ns(ns); 123 } 124 125 struct seq_operations; 126 extern const struct seq_operations proc_uid_seq_operations; 127 extern const struct seq_operations proc_gid_seq_operations; 128 extern const struct seq_operations proc_projid_seq_operations; 129 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 130 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 131 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 132 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 133 extern int proc_setgroups_show(struct seq_file *m, void *v); 134 extern bool userns_may_setgroups(const struct user_namespace *ns); 135 extern bool in_userns(const struct user_namespace *ancestor, 136 const struct user_namespace *child); 137 extern bool current_in_userns(const struct user_namespace *target_ns); 138 struct ns_common *ns_get_owner(struct ns_common *ns); 139 #else 140 141 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 142 { 143 return &init_user_ns; 144 } 145 146 static inline int create_user_ns(struct cred *new) 147 { 148 return -EINVAL; 149 } 150 151 static inline int unshare_userns(unsigned long unshare_flags, 152 struct cred **new_cred) 153 { 154 if (unshare_flags & CLONE_NEWUSER) 155 return -EINVAL; 156 return 0; 157 } 158 159 static inline void put_user_ns(struct user_namespace *ns) 160 { 161 } 162 163 static inline bool userns_may_setgroups(const struct user_namespace *ns) 164 { 165 return true; 166 } 167 168 static inline bool in_userns(const struct user_namespace *ancestor, 169 const struct user_namespace *child) 170 { 171 return true; 172 } 173 174 static inline bool current_in_userns(const struct user_namespace *target_ns) 175 { 176 return true; 177 } 178 179 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 180 { 181 return ERR_PTR(-EPERM); 182 } 183 #endif 184 185 #endif /* _LINUX_USER_H */ 186