1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 9c718583a237..77baff022f71 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -16,6 +16,7 @@
 
 
 #include <linux/kernel.h>
+#include <linux/sched.h>
 #include <linux/pci.h>
 #include <linux/stat.h>
 #include <linux/topology.h>
@@ -484,6 +485,21 @@ pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
 #endif /* HAVE_PCI_LEGACY */
 
 #ifdef HAVE_PCI_MMAP
+
+static int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma)
+{
+        unsigned long nr, start, size;
+
+        nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+        start = vma->vm_pgoff;
+        size = pci_resource_len(pdev, resno) >> PAGE_SHIFT;
+        if (start < size && size - start >= nr)
+                return 1;
+        WARN(1, "process \"%s\" tried to map 0x%08lx-0x%08lx on %s BAR %d (size 0x%08lx)\n",
+                current->comm, start, start+nr, pci_name(pdev), resno, size);
+        return 0;
+}
+
 /**
  * pci_mmap_resource - map a PCI resource into user memory space
  * @kobj: kobject for mapping
@@ -510,6 +526,9 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
         if (i >= PCI_ROM_RESOURCE)
                 return -ENODEV;
 
+        if (!pci_mmap_fits(pdev, i, vma))
+                return -EINVAL;
+
         /* pci_mmap_page_range() expects the same kind of entry as coming
          * from /proc/bus/pci/ which is a "user visible" value. If this is
          * different from the resource itself, arch will do necessary fixup.