diff options
Diffstat (limited to 'kernel/user_namespace.c')
| -rw-r--r-- | kernel/user_namespace.c | 55 |
1 files changed, 30 insertions, 25 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 0b0b95418b16..03cb63883d04 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -21,6 +21,7 @@ #include <linux/fs_struct.h> #include <linux/bsearch.h> #include <linux/sort.h> +#include <linux/nstree.h> static struct kmem_cache *user_ns_cachep __ro_after_init; static DEFINE_MUTEX(userns_state_mutex); @@ -124,12 +125,11 @@ int create_user_ns(struct cred *new) goto fail_dec; ns->parent_could_setfcap = cap_raised(new->cap_effective, CAP_SETFCAP); - ret = ns_alloc_inum(&ns->ns); + + ret = ns_common_init(ns); if (ret) goto fail_free; - ns->ns.ops = &userns_operations; - refcount_set(&ns->ns.count, 1); /* Leave the new->user_ns reference with the new user namespace. */ ns->parent = parent_ns; ns->level = parent_ns->level + 1; @@ -159,12 +159,13 @@ int create_user_ns(struct cred *new) goto fail_keyring; set_cred_user_ns(new, ns); + ns_tree_add(ns); return 0; fail_keyring: #ifdef CONFIG_PERSISTENT_KEYRINGS key_put(ns->persistent_keyring_register); #endif - ns_free_inum(&ns->ns); + ns_common_free(ns); fail_free: kmem_cache_free(user_ns_cachep, ns); fail_dec: @@ -201,6 +202,7 @@ static void free_user_ns(struct work_struct *work) do { struct ucounts *ucounts = ns->ucounts; parent = ns->parent; + ns_tree_remove(ns); if (ns->gid_map.nr_extents > UID_GID_MAP_MAX_BASE_EXTENTS) { kfree(ns->gid_map.forward); kfree(ns->gid_map.reverse); @@ -218,11 +220,12 @@ static void free_user_ns(struct work_struct *work) #endif retire_userns_sysctls(ns); key_free_user_ns(ns); - ns_free_inum(&ns->ns); - kmem_cache_free(user_ns_cachep, ns); + ns_common_free(ns); + /* Concurrent nstree traversal depends on a grace period. */ + kfree_rcu(ns, ns.ns_rcu); dec_user_namespaces(ucounts); ns = parent; - } while (refcount_dec_and_test(&parent->ns.count)); + } while (ns_ref_put(parent)); } void __put_user_ns(struct user_namespace *ns) @@ -238,7 +241,7 @@ EXPORT_SYMBOL(__put_user_ns); struct idmap_key { bool map_up; /* true -> id from kid; false -> kid from id */ u32 id; /* id to find */ - u32 count; /* == 0 unless used with map_id_range_down() */ + u32 count; }; /* @@ -343,16 +346,19 @@ u32 map_id_down(struct uid_gid_map *map, u32 id) * UID_GID_MAP_MAX_BASE_EXTENTS. */ static struct uid_gid_extent * -map_id_up_base(unsigned extents, struct uid_gid_map *map, u32 id) +map_id_range_up_base(unsigned extents, struct uid_gid_map *map, u32 id, u32 count) { unsigned idx; - u32 first, last; + u32 first, last, id2; + + id2 = id + count - 1; /* Find the matching extent */ for (idx = 0; idx < extents; idx++) { first = map->extent[idx].lower_first; last = first + map->extent[idx].count - 1; - if (id >= first && id <= last) + if (id >= first && id <= last && + (id2 >= first && id2 <= last)) return &map->extent[idx]; } return NULL; @@ -363,28 +369,28 @@ map_id_up_base(unsigned extents, struct uid_gid_map *map, u32 id) * Can only be called if number of mappings exceeds UID_GID_MAP_MAX_BASE_EXTENTS. */ static struct uid_gid_extent * -map_id_up_max(unsigned extents, struct uid_gid_map *map, u32 id) +map_id_range_up_max(unsigned extents, struct uid_gid_map *map, u32 id, u32 count) { struct idmap_key key; key.map_up = true; - key.count = 1; + key.count = count; key.id = id; return bsearch(&key, map->reverse, extents, sizeof(struct uid_gid_extent), cmp_map_id); } -u32 map_id_up(struct uid_gid_map *map, u32 id) +u32 map_id_range_up(struct uid_gid_map *map, u32 id, u32 count) { struct uid_gid_extent *extent; unsigned extents = map->nr_extents; smp_rmb(); if (extents <= UID_GID_MAP_MAX_BASE_EXTENTS) - extent = map_id_up_base(extents, map, id); + extent = map_id_range_up_base(extents, map, id, count); else - extent = map_id_up_max(extents, map, id); + extent = map_id_range_up_max(extents, map, id, count); /* Map the id or note failure */ if (extent) @@ -395,6 +401,11 @@ u32 map_id_up(struct uid_gid_map *map, u32 id) return id; } +u32 map_id_up(struct uid_gid_map *map, u32 id) +{ + return map_id_range_up(map, id, 1); +} + /** * make_kuid - Map a user-namespace uid pair into a kuid. * @ns: User namespace that the uid is in @@ -853,9 +864,8 @@ static int sort_idmaps(struct uid_gid_map *map) cmp_extents_forward, NULL); /* Only copy the memory from forward we actually need. */ - map->reverse = kmemdup(map->forward, - map->nr_extents * sizeof(struct uid_gid_extent), - GFP_KERNEL); + map->reverse = kmemdup_array(map->forward, map->nr_extents, + sizeof(struct uid_gid_extent), GFP_KERNEL); if (!map->reverse) return -ENOMEM; @@ -1315,11 +1325,6 @@ bool current_in_userns(const struct user_namespace *target_ns) } EXPORT_SYMBOL(current_in_userns); -static inline struct user_namespace *to_user_ns(struct ns_common *ns) -{ - return container_of(ns, struct user_namespace, ns); -} - static struct ns_common *userns_get(struct task_struct *task) { struct user_namespace *user_ns; @@ -1395,7 +1400,6 @@ static struct user_namespace *userns_owner(struct ns_common *ns) const struct proc_ns_operations userns_operations = { .name = "user", - .type = CLONE_NEWUSER, .get = userns_get, .put = userns_put, .install = userns_install, @@ -1406,6 +1410,7 @@ const struct proc_ns_operations userns_operations = { static __init int user_namespaces_init(void) { user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC | SLAB_ACCOUNT); + ns_tree_add(&init_user_ns); return 0; } subsys_initcall(user_namespaces_init); |