[PATCH 3.16.y-ckt 099/168] ixgbe: Fix possible null-dereference in error path

[Luis Henriques]

3.16.7-ckt3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mark Rustad <mark.d.rustad at intel.com>

commit 508a8c9e264e1057f663e578c47c5ffa00adb160 upstream.

In ixgbe_probe, the code at label err_dma can dereference adapter
when it has a NULL value. The check is there to avoid disabling a
disabled device. When adapter is NULL, treat it as if the device
is enabled, because it is enabled in that case.

Signed-off-by: Mark Rustad <mark.d.rustad at intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt at intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 889005922c33..c4d560d7dabb 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8477,7 +8477,7 @@ err_alloc_etherdev:
 				     pci_select_bars(pdev, IORESOURCE_MEM));
 err_pci_reg:
 err_dma:
-	if (!test_and_set_bit(__IXGBE_DISABLED, &adapter->state))
+	if (!adapter || !test_and_set_bit(__IXGBE_DISABLED, &adapter->state))
 		pci_disable_device(pdev);
 	return err;
 }
-- 
2.1.3