diff options
-rw-r--r-- | include/linux/user_namespace.h | 9 | ||||
-rw-r--r-- | kernel/pid_namespace.c | 4 | ||||
-rw-r--r-- | kernel/user_namespace.c | 20 |
3 files changed, 24 insertions, 9 deletions
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 32354b4b4b2b..4005877bb8b6 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -112,8 +112,9 @@ extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); extern int proc_setgroups_show(struct seq_file *m, void *v); extern bool userns_may_setgroups(const struct user_namespace *ns); +extern bool in_userns(const struct user_namespace *ancestor, + const struct user_namespace *child); extern bool current_in_userns(const struct user_namespace *target_ns); - struct ns_common *ns_get_owner(struct ns_common *ns); #else @@ -144,6 +145,12 @@ static inline bool userns_may_setgroups(const struct user_namespace *ns) return true; } +static inline bool in_userns(const struct user_namespace *ancestor, + const struct user_namespace *child) +{ + return true; +} + static inline bool current_in_userns(const struct user_namespace *target_ns) { return true; diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 74a5a7255b4d..4918314893bc 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -101,6 +101,10 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns int i; int err; + err = -EINVAL; + if (!in_userns(parent_pid_ns->user_ns, user_ns)) + goto out; + err = -ENOSPC; if (level > MAX_PID_NS_LEVEL) goto out; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 2f735cbe05e8..c490f1e4313b 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -986,17 +986,21 @@ bool userns_may_setgroups(const struct user_namespace *ns) } /* - * Returns true if @ns is the same namespace as or a descendant of - * @target_ns. + * Returns true if @child is the same namespace or a descendant of + * @ancestor. */ +bool in_userns(const struct user_namespace *ancestor, + const struct user_namespace *child) +{ + const struct user_namespace *ns; + for (ns = child; ns->level > ancestor->level; ns = ns->parent) + ; + return (ns == ancestor); +} + 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; + return in_userns(target_ns, current_user_ns()); } static inline struct user_namespace *to_user_ns(struct ns_common *ns) |