diff --git a/include/net/bluetooth/hci_sock.h b/include/net/bluetooth/hci_sock.h
index 9949870f7d78..1cd63d4da00b 100644
--- a/include/net/bluetooth/hci_sock.h
+++ b/include/net/bluetooth/hci_sock.h
@@ -168,6 +168,7 @@ struct hci_inquiry_req {
 	__u16 dev_id;
 	__u16 flags;
 	__u8  lap[3];
+#define HCI_INQUIRY_MAX_TIMEOUT		30
 	__u8  length;
 	__u8  num_rsp;
 };
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index e1a545c8a69f..104babf67351 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1343,6 +1343,11 @@ int hci_inquiry(void __user *arg)
 		goto done;
 	}
 
+	if (ir.length > HCI_INQUIRY_MAX_TIMEOUT) {
+		err = -EINVAL;
+		goto done;
+	}
+
 	hci_dev_lock(hdev);
 	if (inquiry_cache_age(hdev) > INQUIRY_CACHE_AGE_MAX ||
 	    inquiry_cache_empty(hdev) || ir.flags & IREQ_CACHE_FLUSH) {