diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 71ad289fcb8e..f5fd860a0540 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -14,6 +14,8 @@
 #include <linux/capability.h>
 #include <linux/uaccess.h>
 #include <linux/security.h>
+#include <linux/panic.h>
+#include <linux/sched.h>
 #include <asm/byteorder.h>
 #include "pci.h"
 
@@ -39,13 +41,16 @@ static ssize_t proc_bus_pci_read(struct file *file, char __user *buf,
 	 * undefined locations (think of Intel PIIX4 as a typical example).
 	 */
 
-	if (capable(CAP_SYS_ADMIN))
+	if (file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN))
 		size = dev->cfg_size;
 	else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
 		size = 128;
 	else
 		size = 64;
 
+	if (!nbytes)
+		return 0;
+
 	if (pos >= size)
 		return 0;
 	if (nbytes >= size)
@@ -122,6 +127,15 @@ static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf,
 	if (ret)
 		return ret;
 
+	if (!nbytes)
+		return 0;
+
+	if (resource_is_exclusive(&dev->driver_exclusive_resource, pos, nbytes)) {
+		pci_warn_once(dev, "%s: Unexpected write to kernel-exclusive config offset %x",
+			      current->comm, pos);
+		add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+	}
+
 	if (pos >= size)
 		return 0;
 	if (nbytes >= size)