diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 8297e5b..9217169 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -72,6 +72,7 @@
 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 current_in_userns(const struct user_namespace *target_ns);
 #else
 
 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
@@ -100,6 +101,11 @@
 {
 	return true;
 }
+
+static inline bool current_in_userns(const struct user_namespace *target_ns)
+{
+	return true;
+}
 #endif
 
 #endif /* _LINUX_USER_H */
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 9bafc21..68f5942 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -938,6 +938,20 @@
 	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);
diff --git a/security/commoncap.c b/security/commoncap.c
index e7fadde..e109e6d 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -455,6 +455,8 @@
 
 	if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
 		return 0;
+	if (!current_in_userns(bprm->file->f_path.mnt->mnt_sb->s_user_ns))
+		return 0;
 
 	rc = get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
 	if (rc < 0) {