[PATCH 4.18 122/168] net: ena: fix missing lock during device destruction

From: Greg Kroah-Hartman
Date: Mon Oct 08 2018 - 14:51:31 EST


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

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

From: Netanel Belgazal <netanel@xxxxxxxxxx>

[ Upstream commit 944b28aa2982b4590d4d4dfc777cf85135dca2c0 ]

acquire the rtnl_lock during device destruction to avoid
using partially destroyed device.

ena_remove() shares almost the same logic as ena_destroy_device(),
so use ena_destroy_device() and avoid duplications.

Signed-off-by: Netanel Belgazal <netanel@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/amazon/ena/ena_netdev.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)

--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -3420,24 +3420,18 @@ static void ena_remove(struct pci_dev *p

unregister_netdev(netdev);

- /* Reset the device only if the device is running. */
+ /* If the device is running then we want to make sure the device will be
+ * reset to make sure no more events will be issued by the device.
+ */
if (test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
- ena_com_dev_reset(ena_dev, adapter->reset_reason);
+ set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);

- ena_free_mgmnt_irq(adapter);
-
- ena_disable_msix(adapter);
+ rtnl_lock();
+ ena_destroy_device(adapter, true);
+ rtnl_unlock();

free_netdev(netdev);

- ena_com_mmio_reg_read_request_destroy(ena_dev);
-
- ena_com_abort_admin_commands(ena_dev);
-
- ena_com_wait_for_abort_completion(ena_dev);
-
- ena_com_admin_destroy(ena_dev);
-
ena_com_rss_destroy(ena_dev);

ena_com_delete_debug_area(ena_dev);