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 /* Register of per-UID persistent keyrings for this namespace */ 68 #ifdef CONFIG_PERSISTENT_KEYRINGS 69 struct key *persistent_keyring_register; 70 struct rw_semaphore persistent_keyring_register_sem; 71 #endif 72 struct work_struct work; 73 #ifdef CONFIG_SYSCTL 74 struct ctl_table_set set; 75 struct ctl_table_header *sysctls; 76 #endif 77 struct ucounts *ucounts; 78 int ucount_max[UCOUNT_COUNTS]; 79 } __randomize_layout; 80 81 struct ucounts { 82 struct hlist_node node; 83 struct user_namespace *ns; 84 kuid_t uid; 85 int count; 86 atomic_t ucount[UCOUNT_COUNTS]; 87 }; 88 89 extern struct user_namespace init_user_ns; 90 91 bool setup_userns_sysctls(struct user_namespace *ns); 92 void retire_userns_sysctls(struct user_namespace *ns); 93 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 94 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 95 96 #ifdef CONFIG_USER_NS 97 98 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 99 { 100 if (ns) 101 atomic_inc(&ns->count); 102 return ns; 103 } 104 105 extern int create_user_ns(struct cred *new); 106 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 107 extern void __put_user_ns(struct user_namespace *ns); 108 109 static inline void put_user_ns(struct user_namespace *ns) 110 { 111 if (ns && atomic_dec_and_test(&ns->count)) 112 __put_user_ns(ns); 113 } 114 115 struct seq_operations; 116 extern const struct seq_operations proc_uid_seq_operations; 117 extern const struct seq_operations proc_gid_seq_operations; 118 extern const struct seq_operations proc_projid_seq_operations; 119 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 120 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 121 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 122 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 123 extern int proc_setgroups_show(struct seq_file *m, void *v); 124 extern bool userns_may_setgroups(const struct user_namespace *ns); 125 extern bool in_userns(const struct user_namespace *ancestor, 126 const struct user_namespace *child); 127 extern bool current_in_userns(const struct user_namespace *target_ns); 128 struct ns_common *ns_get_owner(struct ns_common *ns); 129 #else 130 131 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 132 { 133 return &init_user_ns; 134 } 135 136 static inline int create_user_ns(struct cred *new) 137 { 138 return -EINVAL; 139 } 140 141 static inline int unshare_userns(unsigned long unshare_flags, 142 struct cred **new_cred) 143 { 144 if (unshare_flags & CLONE_NEWUSER) 145 return -EINVAL; 146 return 0; 147 } 148 149 static inline void put_user_ns(struct user_namespace *ns) 150 { 151 } 152 153 static inline bool userns_may_setgroups(const struct user_namespace *ns) 154 { 155 return true; 156 } 157 158 static inline bool in_userns(const struct user_namespace *ancestor, 159 const struct user_namespace *child) 160 { 161 return true; 162 } 163 164 static inline bool current_in_userns(const struct user_namespace *target_ns) 165 { 166 return true; 167 } 168 169 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 170 { 171 return ERR_PTR(-EPERM); 172 } 173 #endif 174 175 #endif /* _LINUX_USER_H */ 176