[PATCH AUTOSEL 4.19 45/68] net: ena: fix crash during failed resume from hibernation

From: Sasha Levin
Date: Thu Nov 29 2018 - 00:59:42 EST

From: Arthur Kiyanovski <akiyano@xxxxxxxxxx>

[ Upstream commit e76ad21d070f79e566ac46ce0b0584c3c93e1b43 ]

During resume from hibernation if ena_restore_device fails,
ena_com_dev_reset() is called, and uses the readless read mechanism,
which was already destroyed by the call to
ena_com_mmio_reg_read_request_destroy(). This causes a NULL pointer

In this commit we switch the call order of the above two functions
to avoid this crash.

Fixes: d7703ddbd7c9 ("net: ena: fix rare bug when failed restart/resume is followed by driver removal")
Signed-off-by: Arthur Kiyanovski <akiyano@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index d906293ce07d..4b73131a0f20 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -2627,8 +2627,8 @@ static int ena_restore_device(struct ena_adapter *adapter)
- ena_com_mmio_reg_read_request_destroy(ena_dev);
ena_com_dev_reset(ena_dev, ENA_REGS_RESET_DRIVER_INVALID_STATE);
+ ena_com_mmio_reg_read_request_destroy(ena_dev);
clear_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
clear_bit(ENA_FLAG_ONGOING_RESET, &adapter->flags);