ixgbe: fix use of list_for_each in ixgbe_enumerate_functions

Fix a bug in the misuse of the list_for_each macro to loop over every
entry in the bus_list. Instead of attempting to loop over the list from
a random entry point, go up to the bus and use the real list_head entry
point. This prevents the possible read or write of unallocated or
incorrectly addressed memory.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 9aa9d0b..4268a89 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7973,23 +7973,20 @@ static const struct net_device_ops ixgbe_netdev_ops = {
  **/
 static inline int ixgbe_enumerate_functions(struct ixgbe_adapter *adapter)
 {
-       struct list_head *entry;
+       struct pci_dev *entry;
        int physfns = 0;
 
        /* Some cards can not use the generic count PCIe functions method,
         * because they are behind a parent switch, so we hardcode these with
         * the correct number of functions.
         */
-       if (ixgbe_pcie_from_parent(&adapter->hw)) {
+       if (ixgbe_pcie_from_parent(&adapter->hw))
                physfns = 4;
-       } else {
-               list_for_each(entry, &adapter->pdev->bus_list) {
-                       struct pci_dev *pdev =
-                               list_entry(entry, struct pci_dev, bus_list);
-                       /* don't count virtual functions */
-                       if (!pdev->is_virtfn)
-                               physfns++;
-               }
+
+       list_for_each_entry(entry, &adapter->pdev->bus->devices, bus_list) {
+               /* don't count virtual functions */
+               if (!entry->is_virtfn)
+                       physfns++;
        }
 
        return physfns;