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>

1 files changed, 10 insertions, 1 deletions

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);