lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20171114190327.57899-6-jeffrey.t.kirsher@intel.com>
Date:   Tue, 14 Nov 2017 11:03:22 -0800
From:   Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To:     davem@...emloft.net
Cc:     Jacob Keller <jacob.e.keller@...el.com>, netdev@...r.kernel.org,
        nhorman@...hat.com, sassmann@...hat.com, jogreene@...hat.com,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next 05/10] i40evf: hold the critical task bit lock while opening

From: Jacob Keller <jacob.e.keller@...el.com>

If i40evf_open() is called quickly at the same time as a reset occurs
(such as via ethtool) it is possible for the device to attempt to open
while a reset is in progress. This occurs because the driver was not
holding the critical task bit lock during i40evf_open, nor was it
holding it around the call to i40evf_up_complete() in
i40evf_reset_task().

We didn't hold the lock previously because calls to i40evf_down() would
take the bit lock directly, and this would have caused a deadlock.

To avoid this, we'll move the bit lock handling out of i40evf_down() and
into the callers of this function. Additionally, we'll now hold the bit
lock over the entire set of steps when going up or down, to ensure that
we remain consistent.

Ultimately this causes us to serialize the transitions between down and
up properly, and avoid changing status while we're resetting.

Signed-off-by: Jacob Keller <jacob.e.keller@...el.com>
Tested-by: Andrew Bowers <andrewx.bowers@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
 drivers/net/ethernet/intel/i40evf/i40evf_main.c | 40 +++++++++++++++++++------
 1 file changed, 31 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index 9a945ffef1e1..45cff725ed31 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -1035,6 +1035,8 @@ static void i40evf_configure(struct i40evf_adapter *adapter)
 /**
  * i40evf_up_complete - Finish the last steps of bringing up a connection
  * @adapter: board private structure
+ *
+ * Expects to be called while holding the __I40EVF_IN_CRITICAL_TASK bit lock.
  **/
 static void i40evf_up_complete(struct i40evf_adapter *adapter)
 {
@@ -1052,6 +1054,8 @@ static void i40evf_up_complete(struct i40evf_adapter *adapter)
 /**
  * i40e_down - Shutdown the connection processing
  * @adapter: board private structure
+ *
+ * Expects to be called while holding the __I40EVF_IN_CRITICAL_TASK bit lock.
  **/
 void i40evf_down(struct i40evf_adapter *adapter)
 {
@@ -1061,10 +1065,6 @@ void i40evf_down(struct i40evf_adapter *adapter)
 	if (adapter->state <= __I40EVF_DOWN_PENDING)
 		return;
 
-	while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK,
-				&adapter->crit_section))
-		usleep_range(500, 1000);
-
 	netif_carrier_off(netdev);
 	netif_tx_disable(netdev);
 	adapter->link_up = false;
@@ -1097,7 +1097,6 @@ void i40evf_down(struct i40evf_adapter *adapter)
 		adapter->aq_required |= I40EVF_FLAG_AQ_DISABLE_QUEUES;
 	}
 
-	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
 	mod_timer_pending(&adapter->watchdog_timer, jiffies + 1);
 }
 
@@ -1960,8 +1959,6 @@ static void i40evf_reset_task(struct work_struct *work)
 
 	adapter->aq_required |= I40EVF_FLAG_AQ_ADD_MAC_FILTER;
 	adapter->aq_required |= I40EVF_FLAG_AQ_ADD_VLAN_FILTER;
-	clear_bit(__I40EVF_IN_CLIENT_TASK, &adapter->crit_section);
-	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
 	i40evf_misc_irq_enable(adapter);
 
 	mod_timer(&adapter->watchdog_timer, jiffies + 2);
@@ -1998,9 +1995,13 @@ static void i40evf_reset_task(struct work_struct *work)
 		adapter->state = __I40EVF_DOWN;
 		wake_up(&adapter->down_waitqueue);
 	}
+	clear_bit(__I40EVF_IN_CLIENT_TASK, &adapter->crit_section);
+	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
 
 	return;
 reset_err:
+	clear_bit(__I40EVF_IN_CLIENT_TASK, &adapter->crit_section);
+	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
 	dev_err(&adapter->pdev->dev, "failed to allocate resources during reinit\n");
 	i40evf_close(netdev);
 }
@@ -2244,8 +2245,14 @@ static int i40evf_open(struct net_device *netdev)
 		return -EIO;
 	}
 
-	if (adapter->state != __I40EVF_DOWN)
-		return -EBUSY;
+	while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK,
+				&adapter->crit_section))
+		usleep_range(500, 1000);
+
+	if (adapter->state != __I40EVF_DOWN) {
+		err = -EBUSY;
+		goto err_unlock;
+	}
 
 	/* allocate transmit descriptors */
 	err = i40evf_setup_all_tx_resources(adapter);
@@ -2269,6 +2276,8 @@ static int i40evf_open(struct net_device *netdev)
 
 	i40evf_irq_enable(adapter, true);
 
+	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
+
 	return 0;
 
 err_req_irq:
@@ -2278,6 +2287,8 @@ static int i40evf_open(struct net_device *netdev)
 	i40evf_free_all_rx_resources(adapter);
 err_setup_tx:
 	i40evf_free_all_tx_resources(adapter);
+err_unlock:
+	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
 
 	return err;
 }
@@ -2301,6 +2312,9 @@ static int i40evf_close(struct net_device *netdev)
 	if (adapter->state <= __I40EVF_DOWN_PENDING)
 		return 0;
 
+	while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK,
+				&adapter->crit_section))
+		usleep_range(500, 1000);
 
 	set_bit(__I40E_VSI_DOWN, adapter->vsi.state);
 	if (CLIENT_ENABLED(adapter))
@@ -2310,6 +2324,8 @@ static int i40evf_close(struct net_device *netdev)
 	adapter->state = __I40EVF_DOWN_PENDING;
 	i40evf_free_traffic_irqs(adapter);
 
+	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
+
 	/* We explicitly don't free resources here because the hardware is
 	 * still active and can DMA into memory. Resources are cleared in
 	 * i40evf_virtchnl_completion() after we get confirmation from the PF
@@ -2992,6 +3008,10 @@ static int i40evf_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	netif_device_detach(netdev);
 
+	while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK,
+				&adapter->crit_section))
+		usleep_range(500, 1000);
+
 	if (netif_running(netdev)) {
 		rtnl_lock();
 		i40evf_down(adapter);
@@ -3000,6 +3020,8 @@ static int i40evf_suspend(struct pci_dev *pdev, pm_message_t state)
 	i40evf_free_misc_irq(adapter);
 	i40evf_reset_interrupt_capability(adapter);
 
+	clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
+
 	retval = pci_save_state(pdev);
 	if (retval)
 		return retval;
-- 
2.14.2

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ