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From:   Sasha Levin <sashal@kernel.org>
To:     stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Arthur Kiyanovski <akiyano@amazon.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 45/68] net: ena: fix crash during failed resume from hibernation
Date:   Thu, 29 Nov 2018 00:55:36 -0500
Message-Id: <20181129055559.159228-45-sashal@kernel.org>
In-Reply-To: <20181129055559.159228-1-sashal@kernel.org>
References: <20181129055559.159228-1-sashal@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Arthur Kiyanovski <akiyano@amazon.com>

[ 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
reference.

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@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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_abort_admin_commands(ena_dev);
 	ena_com_wait_for_abort_completion(ena_dev);
 	ena_com_admin_destroy(ena_dev);
-	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);
 err:
 	clear_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
 	clear_bit(ENA_FLAG_ONGOING_RESET, &adapter->flags);
-- 
2.17.1