diff options
Diffstat (limited to 'kernel/user_namespace.c')
| -rw-r--r-- | kernel/user_namespace.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index a965df4b54f5..74a8e4aead9a 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -944,6 +944,20 @@ bool userns_may_setgroups(const struct user_namespace *ns) return allowed; } +/* + * Returns true if @ns is the same namespace as or a descendant of + * @target_ns. + */ +bool current_in_userns(const struct user_namespace *target_ns) +{ + struct user_namespace *ns; + for (ns = current_user_ns(); ns; ns = ns->parent) { + if (ns == target_ns) + return true; + } + return false; +} + static inline struct user_namespace *to_user_ns(struct ns_common *ns) { return container_of(ns, struct user_namespace, ns); @@ -996,12 +1010,36 @@ static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns) return commit_creds(cred); } +struct ns_common *ns_get_owner(struct ns_common *ns) +{ + struct user_namespace *my_user_ns = current_user_ns(); + struct user_namespace *owner, *p; + + /* See if the owner is in the current user namespace */ + owner = p = ns->ops->owner(ns); + for (;;) { + if (!p) + return ERR_PTR(-EPERM); + if (p == my_user_ns) + break; + p = p->parent; + } + + return &get_user_ns(owner)->ns; +} + +static struct user_namespace *userns_owner(struct ns_common *ns) +{ + return to_user_ns(ns)->parent; +} + const struct proc_ns_operations userns_operations = { .name = "user", .type = CLONE_NEWUSER, .get = userns_get, .put = userns_put, .install = userns_install, + .owner = userns_owner, }; static __init int user_namespaces_init(void) |