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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Neil Horman <nhorman@tuxdriver.com>,
        Shrikrishna Khare <skhare@vmware.com>,
        "VMware, Inc." <pv-drivers@vmware.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 3.18 016/121] vmxnet3: ensure that adapter is in proper state during force_close
Date:   Wed, 11 Apr 2018 20:35:19 +0200
Message-Id: <20180411183457.148275052@linuxfoundation.org>
In-Reply-To: <20180411183456.195010921@linuxfoundation.org>
References: <20180411183456.195010921@linuxfoundation.org>
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3.18-stable review patch.  If anyone has any objections, please let me know.

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

From: Neil Horman <nhorman@tuxdriver.com>


[ Upstream commit 1c4d5f51a812a82de97beee24f48ed05c65ebda5 ]

There are several paths in vmxnet3, where settings changes cause the
adapter to be brought down and back up (vmxnet3_set_ringparam among
them).  Should part of the reset operation fail, these paths call
vmxnet3_force_close, which enables all napi instances prior to calling
dev_close (with the expectation that vmxnet3_close will then properly
disable them again).  However, vmxnet3_force_close neglects to clear
VMXNET3_STATE_BIT_QUIESCED prior to calling dev_close.  As a result
vmxnet3_quiesce_dev (called from vmxnet3_close), returns early, and
leaves all the napi instances in a enabled state while the device itself
is closed.  If a device in this state is activated again, napi_enable
will be called on already enabled napi_instances, leading to a BUG halt.

The fix is to simply enausre that the QUIESCED bit is cleared in
vmxnet3_force_close to allow quesence to be completed properly on close.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Shrikrishna Khare <skhare@vmware.com>
CC: "VMware, Inc." <pv-drivers@vmware.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/vmxnet3/vmxnet3_drv.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -2648,6 +2648,11 @@ vmxnet3_force_close(struct vmxnet3_adapt
 	/* we need to enable NAPI, otherwise dev_close will deadlock */
 	for (i = 0; i < adapter->num_rx_queues; i++)
 		napi_enable(&adapter->rx_queue[i].napi);
+	/*
+	 * Need to clear the quiesce bit to ensure that vmxnet3_close
+	 * can quiesce the device properly
+	 */
+	clear_bit(VMXNET3_STATE_BIT_QUIESCED, &adapter->state);
 	dev_close(adapter->netdev);
 }