[net PATCH] octeontx2-pf: Fix interface down flag on error

In the existing code while changing the number of TX/RX
queues using ethtool the PF/VF interface resources are
freed and reallocated (otx2_stop and otx2_open is called)
if the device is in running state. If any resource allocation
fails in otx2_open, driver free already allocated resources
and return. But again, when the number of queues changes
as the device state still running oxt2_stop is called.
In which we try to free already freed resources leading
to driver crash.
This patch fixes the issue by setting the INTF_DOWN flag on
error and free the resources in otx2_stop only if the flag is
not set.

Fixes: 50fe6c02e5ad ("octeontx2-pf: Register and handle link notifications")
Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <redacted>
---
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c | 7 +++----
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c      | 5 +++++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
index 8df748e0677b..b906a0eb6e0d 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c

@@ -298,15 +298,14 @@ static int otx2_set_channels(struct net_device *dev,
 	err = otx2_set_real_num_queues(dev, channel->tx_count,
 				       channel->rx_count);
 	if (err)
-		goto fail;
+		return err;
 
 	pfvf->hw.rx_queues = channel->rx_count;
 	pfvf->hw.tx_queues = channel->tx_count;
 	pfvf->qset.cq_cnt = pfvf->hw.tx_queues +  pfvf->hw.rx_queues;
 
-fail:
 	if (if_up)
-		dev->netdev_ops->ndo_open(dev);
+		err = dev->netdev_ops->ndo_open(dev);
 
 	netdev_info(dev, "Setting num Tx rings to %d, Rx rings to %d success\n",
 		    pfvf->hw.tx_queues, pfvf->hw.rx_queues);

@@ -410,7 +409,7 @@ static int otx2_set_ringparam(struct net_device *netdev,
 	qs->rqe_cnt = rx_count;
 
 	if (if_up)
-		netdev->netdev_ops->ndo_open(netdev);
+		return netdev->netdev_ops->ndo_open(netdev);
 
 	return 0;
 }

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index f300b807a85b..2c24944a4dba 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c

@@ -1662,6 +1662,7 @@ int otx2_open(struct net_device *netdev)
 err_tx_stop_queues:
 	netif_tx_stop_all_queues(netdev);
 	netif_carrier_off(netdev);
+	pf->flags |= OTX2_FLAG_INTF_DOWN;
 err_free_cints:
 	otx2_free_cints(pf, qidx);
 	vec = pci_irq_vector(pf->pdev,

@@ -1689,6 +1690,10 @@ int otx2_stop(struct net_device *netdev)
 	struct otx2_rss_info *rss;
 	int qidx, vec, wrk;
 
+	/* If the DOWN flag is set resources are already freed */
+	if (pf->flags & OTX2_FLAG_INTF_DOWN)
+		return 0;
+
 	netif_carrier_off(netdev);
 	netif_tx_stop_all_queues(netdev);
 

-- 
2.17.1

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Sun, 25 Jul 2021 13:29:03 +0530 you wrote:

In the existing code while changing the number of TX/RX
queues using ethtool the PF/VF interface resources are
freed and reallocated (otx2_stop and otx2_open is called)
if the device is in running state. If any resource allocation
fails in otx2_open, driver free already allocated resources
and return. But again, when the number of queues changes
as the device state still running oxt2_stop is called.
In which we try to free already freed resources leading
to driver crash.
This patch fixes the issue by setting the INTF_DOWN flag on
error and free the resources in otx2_stop only if the flag is
not set.

[...]

Here is the summary with links:
  - [net] octeontx2-pf: Fix interface down flag on error
    https://git.kernel.org/netdev/net/c/69f0aeb13bb5

You are awesome, thank you!
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