diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 6030a8235617..eeb7cd94bca0 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -187,6 +187,8 @@ 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);
+
+extern int unprivileged_userns_clone;
 #else
 
 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
diff --git a/kernel/fork.c b/kernel/fork.c
index 0d944e92a43f..172fc8c09973 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -112,6 +112,11 @@
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/task.h>
+#ifdef CONFIG_USER_NS
+extern int unprivileged_userns_clone;
+#else
+#define unprivileged_userns_clone 0
+#endif
 
 /*
  * Minimum number of threads to boot the kernel
@@ -2260,6 +2265,10 @@ __latent_entropy struct task_struct *copy_process(
 	if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS))
 		return ERR_PTR(-EINVAL);
 
+	if ((clone_flags & CLONE_NEWUSER) && !unprivileged_userns_clone)
+		if (!capable(CAP_SYS_ADMIN))
+			return ERR_PTR(-EPERM);
+
 	/*
 	 * Thread groups must share signals as well, and detached threads
 	 * can only be started up within the thread group.
@@ -3406,6 +3415,12 @@ int ksys_unshare(unsigned long unshare_flags)
 	if (unshare_flags & CLONE_NEWNS)
 		unshare_flags |= CLONE_FS;
 
+	if ((unshare_flags & CLONE_NEWUSER) && !unprivileged_userns_clone) {
+		err = -EPERM;
+		if (!capable(CAP_SYS_ADMIN))
+			goto bad_unshare_out;
+	}
+
 	err = check_unshare_flags(unshare_flags);
 	if (err)
 		goto bad_unshare_out;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 157f7ce2942d..9d198d7f482b 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -63,6 +63,7 @@
 #include <linux/mount.h>
 #include <linux/userfaultfd_k.h>
 #include <linux/pid.h>
+#include <linux/user_namespace.h>
 
 #include "../lib/kstrtox.h"
 
@@ -1766,6 +1767,15 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= sysrq_sysctl_handler,
 	},
 #endif
+#ifdef CONFIG_USER_NS
+	{
+		.procname	= "unprivileged_userns_clone",
+		.data		= &unprivileged_userns_clone,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#endif
 #ifdef CONFIG_PROC_SYSCTL
 	{
 		.procname	= "cad_pid",
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index ce4d99df5f0e..eb7406b5d4d0 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -22,6 +22,12 @@
 #include <linux/bsearch.h>
 #include <linux/sort.h>
 
+/*
+ * sysctl determining whether unprivileged users may unshare a new
+ * userns.  Allowed by default
+ */
+int unprivileged_userns_clone = 1;
+
 static struct kmem_cache *user_ns_cachep __ro_after_init;
 static DEFINE_MUTEX(userns_state_mutex);