diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 71ad289fcb8e..fcbd75d53ac5 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -46,6 +46,9 @@ static ssize_t proc_bus_pci_read(struct file *file, char __user *buf,
 	else
 		size = 64;
 
+	if (!nbytes)
+		return 0;
+
 	if (pos >= size)
 		return 0;
 	if (nbytes >= size)
@@ -122,6 +125,9 @@ static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf,
 	if (ret)
 		return ret;
 
+	if (!nbytes)
+		return 0;
+
 	if (pos >= size)
 		return 0;
 	if (nbytes >= size)