diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 1be0b9f93366..44cb37b5a4dc 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -1004,7 +1004,7 @@ static long mon_bin_ioctl(struct file *file, unsigned int cmd, unsigned long arg
 
 		mutex_lock(&rp->fetch_lock);
 		spin_lock_irqsave(&rp->b_lock, flags);
-		mon_free_buff(rp->b_vec, size/CHUNK_SIZE);
+		mon_free_buff(rp->b_vec, rp->b_size/CHUNK_SIZE);
 		kfree(rp->b_vec);
 		rp->b_vec  = vec;
 		rp->b_size = size;