[Intel-wired-lan] [PATCH] igb: close/suspend race in netif_device_detach

[Todd Fujinaka]

Similar to ixgbe, when an interface is part of a namespace it is
possible that igb_close() may be called while __igb_shutdown() is
running which ends up in a double free WARN and/or a BUG in
free_msi_irqs().

Extend the rtnl_lock() to protect the call to netif_device_detach() and
igb_clear_interrupt_scheme() in __igb_shutdown() and check for
netif_device_present() to avoid calling igb_clear_interrupt_scheme() a
second time in igb_close() and igb_remove().

Also extend the rtnl lock in igb_resume() to netif_device_attach().

Signed-off-by: Todd Fujinaka <todd.fujinaka at intel.com>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 4feca69..c040cc7 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2930,7 +2930,10 @@ static void igb_remove(struct pci_dev *pdev)
 
 	unregister_netdev(netdev);
 
-	igb_clear_interrupt_scheme(adapter);
+	rtnl_lock();
+	if (netif_device_present(netdev))
+		igb_clear_interrupt_scheme(adapter);
+	rtnl_unlock();
 
 	pci_iounmap(pdev, adapter->io_addr);
 	if (hw->flash_address)
@@ -3275,7 +3278,9 @@ static int __igb_close(struct net_device *netdev, bool suspending)
 
 int igb_close(struct net_device *netdev)
 {
-	return __igb_close(netdev, false);
+	if (netif_device_present(netdev))
+		return __igb_close(netdev, false);
+	return 0;
 }
 
 /**
@@ -7537,6 +7542,7 @@ static int __igb_shutdown(struct pci_dev *pdev, bool *enable_wake,
 	int retval = 0;
 #endif
 
+	rtnl_lock();
 	netif_device_detach(netdev);
 
 	if (netif_running(netdev))
@@ -7545,6 +7551,7 @@ static int __igb_shutdown(struct pci_dev *pdev, bool *enable_wake,
 	igb_ptp_suspend(adapter);
 
 	igb_clear_interrupt_scheme(adapter);
+	rtnl_unlock();
 
 #ifdef CONFIG_PM
 	retval = pci_save_state(pdev);
@@ -7663,16 +7670,15 @@ static int igb_resume(struct device *dev)
 
 	wr32(E1000_WUS, ~0);
 
-	if (netdev->flags & IFF_UP) {
-		rtnl_lock();
+	rtnl_lock();
+	if (!err && netif_running(netdev))
 		err = __igb_open(netdev, true);
-		rtnl_unlock();
-		if (err)
-			return err;
-	}
 
-	netif_device_attach(netdev);
-	return 0;
+	if (!err)
+		netif_device_attach(netdev);
+	rtnl_unlock();
+
+	return err;
 }
 
 static int igb_runtime_idle(struct device *dev)
-- 
2.7.4