PCI: check mmap range of /proc/bus/pci files too

/proc/bus/pci allows you to mmap resource ranges too, so we should probably be
checking to make sure the mapping is somewhat valid.  Uses the same code as the recent sysfs mmap range checking patch from Linus.

Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

3 files changed, 15 insertions, 2 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index c88485860a0a..388440e0d222 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -569,7 +569,7 @@ void pci_remove_legacy_files(struct pci_bus *b)
 
 #ifdef HAVE_PCI_MMAP
 
-static int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma)
+int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma)
 {
         unsigned long nr, start, size;
 
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9de87e9f98f5..d3e65e29df51 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -10,6 +10,10 @@ extern int pci_uevent(struct device *dev, struct kobj_uevent_env *env);
 extern int pci_create_sysfs_dev_files(struct pci_dev *pdev);
 extern void pci_remove_sysfs_dev_files(struct pci_dev *pdev);
 extern void pci_cleanup_rom(struct pci_dev *dev);
+#ifdef HAVE_PCI_MMAP
+extern int pci_mmap_fits(struct pci_dev *pdev, int resno,
+                         struct vm_area_struct *vma);
+#endif
 
 /**
  * Firmware PM callbacks
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index e1098c302c45..7fb086d39617 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -252,11 +252,20 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
         const struct proc_dir_entry *dp = PDE(inode);
         struct pci_dev *dev = dp->data;
         struct pci_filp_private *fpriv = file->private_data;
-        int ret;
+        int i, ret;
 
         if (!capable(CAP_SYS_RAWIO))
                 return -EPERM;
 
+        /* Make sure the caller is mapping a real resource for this device */
+        for (i = 0; i < PCI_ROM_RESOURCE; i++) {
+                if (pci_mmap_fits(dev, i, vma))
+                        break;
+        }
+
+        if (i >= PCI_ROM_RESOURCE)
+                return -ENODEV;
+
         ret = pci_mmap_page_range(dev, vma,
                                   fpriv->mmap_state,
                                   fpriv->write_combine);