[PATCH 4.4 42/59] ixgbe: handle close/suspend race with netif_device_detach/present

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Emil Tantilov <emil.s.tantilov@intel.com>


[ Upstream commit f7f37e7ff2b9b7eff7fbd035569cab35896869a3 ]

When an interface is part of a namespace it is possible that
ixgbe_close() may be called while __ixgbe_shutdown() is running
which ends up in a double free WARN and/or a BUG in free_msi_irqs().

To handle this situation we extend the rtnl_lock() to protect the
call to netif_device_detach() and ixgbe_clear_interrupt_scheme()
in __ixgbe_shutdown() and check for netif_device_present()
to avoid clearing the interrupts second time in ixgbe_close();

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

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -5878,7 +5878,8 @@ static int ixgbe_close(struct net_device
 
 	ixgbe_ptp_stop(adapter);
 
-	ixgbe_close_suspend(adapter);
+	if (netif_device_present(netdev))
+		ixgbe_close_suspend(adapter);
 
 	ixgbe_fdir_filter_exit(adapter);
 
@@ -5923,14 +5924,12 @@ static int ixgbe_resume(struct pci_dev *
 	if (!err && netif_running(netdev))
 		err = ixgbe_open(netdev);
 
-	rtnl_unlock();
 
-	if (err)
-		return err;
-
-	netif_device_attach(netdev);
+	if (!err)
+		netif_device_attach(netdev);
+	rtnl_unlock();
 
-	return 0;
+	return err;
 }
 #endif /* CONFIG_PM */
 
@@ -5945,14 +5944,14 @@ static int __ixgbe_shutdown(struct pci_d
 	int retval = 0;
 #endif
 
+	rtnl_lock();
 	netif_device_detach(netdev);
 
-	rtnl_lock();
 	if (netif_running(netdev))
 		ixgbe_close_suspend(adapter);
-	rtnl_unlock();
 
 	ixgbe_clear_interrupt_scheme(adapter);
+	rtnl_unlock();
 
 #ifdef CONFIG_PM
 	retval = pci_save_state(pdev);