[PATCH 3.16 058/134] PCI: Fix another sanity check bug in /proc/pci mmap

Ben Hutchings
2017-08-18T13:15:46Z

From: David Woodhouse <dwmw@amazon.co.uk>

commit 17caf56731311c9596e7d38a70c88fcb6afa6a1b upstream.

Don't match MMIO maps with I/O BARs and vice versa.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/pci/proc.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -231,14 +231,20 @@ static int proc_bus_pci_mmap(struct file
{
struct pci_dev *dev = PDE_DATA(file_inode(file));
struct pci_filp_private *fpriv = file->private_data;
- int i, ret, write_combine;
+ int i, ret, write_combine, res_bit;

if (!capable(CAP_SYS_RAWIO))
return -EPERM;

+ if (fpriv->mmap_state == pci_mmap_io)
+ res_bit = IORESOURCE_IO;
+ else
+ res_bit = IORESOURCE_MEM;
+
/* 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, PCI_MMAP_PROCFS))
+ if (dev->resource[i].flags & res_bit &&
+ pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS))
break;
}