diff --git a/fs/mount.h b/fs/mount.h
index 14db05d424f7059d9bd035f88f9c50b719447ee8..e037981d8351657d94a987010d45418c2f488bff 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -10,6 +10,7 @@ struct mnt_namespace {
 	struct mount *	root;
 	struct list_head	list;
 	struct user_namespace	*user_ns;
+	struct ucounts		*ucounts;
 	u64			seq;	/* Sequence number to prevent loops */
 	wait_queue_head_t poll;
 	u64 event;
diff --git a/fs/namespace.c b/fs/namespace.c
index 7bb2cda3bfef50b27f9bb8b3b478cc7aeb3d1049..491b8f3e4c9a0fac5ea248eac833c07044915f3c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2719,9 +2719,20 @@ long do_mount(const char *dev_name, const char __user *dir_name,
 	return retval;
 }
 
+static struct ucounts *inc_mnt_namespaces(struct user_namespace *ns)
+{
+	return inc_ucount(ns, current_euid(), UCOUNT_MNT_NAMESPACES);
+}
+
+static void dec_mnt_namespaces(struct ucounts *ucounts)
+{
+	dec_ucount(ucounts, UCOUNT_MNT_NAMESPACES);
+}
+
 static void free_mnt_ns(struct mnt_namespace *ns)
 {
 	ns_free_inum(&ns->ns);
+	dec_mnt_namespaces(ns->ucounts);
 	put_user_ns(ns->user_ns);
 	kfree(ns);
 }
@@ -2738,14 +2749,22 @@ static atomic64_t mnt_ns_seq = ATOMIC64_INIT(1);
 static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
 {
 	struct mnt_namespace *new_ns;
+	struct ucounts *ucounts;
 	int ret;
 
+	ucounts = inc_mnt_namespaces(user_ns);
+	if (!ucounts)
+		return ERR_PTR(-ENFILE);
+
 	new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
-	if (!new_ns)
+	if (!new_ns) {
+		dec_mnt_namespaces(ucounts);
 		return ERR_PTR(-ENOMEM);
+	}
 	ret = ns_alloc_inum(&new_ns->ns);
 	if (ret) {
 		kfree(new_ns);
+		dec_mnt_namespaces(ucounts);
 		return ERR_PTR(ret);
 	}
 	new_ns->ns.ops = &mntns_operations;
@@ -2756,6 +2775,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
 	init_waitqueue_head(&new_ns->poll);
 	new_ns->event = 0;
 	new_ns->user_ns = get_user_ns(user_ns);
+	new_ns->ucounts = ucounts;
 	return new_ns;
 }
 
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index c6bc980b06a9f59b295b44e3d81f66bc24b840f6..30ffe10cda18e818258879882b383aaf801c1abf 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -30,6 +30,7 @@ enum ucount_type {
 	UCOUNT_UTS_NAMESPACES,
 	UCOUNT_IPC_NAMESPACES,
 	UCOUNT_NET_NAMESPACES,
+	UCOUNT_MNT_NAMESPACES,
 	UCOUNT_CGROUP_NAMESPACES,
 	UCOUNT_COUNTS,
 };
diff --git a/kernel/ucount.c b/kernel/ucount.c
index 205f1a07faac6507239276dc6790b897d28ee1b9..9d20d5dd298af25d0cd95635e217180601703959 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -72,6 +72,7 @@ static struct ctl_table user_table[] = {
 	UCOUNT_ENTRY("max_uts_namespaces"),
 	UCOUNT_ENTRY("max_ipc_namespaces"),
 	UCOUNT_ENTRY("max_net_namespaces"),
+	UCOUNT_ENTRY("max_mnt_namespaces"),
 	UCOUNT_ENTRY("max_cgroup_namespaces"),
 	{ }
 };