diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 0021f4773f7e679077233ca0163658b578c3354d..e58b5959e17c76e67767d29eb68c842ef808496c 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -20,6 +20,7 @@
 #define PTP_MAX_TIMESTAMPS 128
 #define PTP_BUF_TIMESTAMPS 30
 #define PTP_DEFAULT_MAX_VCLOCKS 20
+#define PTP_MAX_VCLOCKS_LIMIT (KMALLOC_MAX_SIZE/(sizeof(int)))
 
 struct timestamp_event_queue {
 	struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
index aefc06ae5d099514959b056b89c2f0bbe455ad7f..02111e6d87a10fdb5989b5a43ef00b08aeb131a5 100644
--- a/drivers/ptp/ptp_sysfs.c
+++ b/drivers/ptp/ptp_sysfs.c
@@ -282,7 +282,7 @@ static ssize_t max_vclocks_store(struct device *dev,
 	size_t size;
 	u32 max;
 
-	if (kstrtou32(buf, 0, &max) || max == 0)
+	if (kstrtou32(buf, 0, &max) || max == 0 || max > PTP_MAX_VCLOCKS_LIMIT)
 		return -EINVAL;
 
 	if (max == ptp->max_vclocks)