From 76825d6a79ec1338e9d684e25fbe21eb375a5027 Mon Sep 17 00:00:00 2001 From: Ronak Doshi Date: Fri, 5 Sep 2025 14:23:12 -0400 Subject: [PATCH] vmxnet3: update MTU after device quiesce [ Upstream commit 43f0999af011fba646e015f0bb08b6c3002a0170 ] Currently, when device mtu is updated, vmxnet3 updates netdev mtu, quiesces the device and then reactivates it for the ESXi to know about the new mtu. So, technically the OS stack can start using the new mtu before ESXi knows about the new mtu. This can lead to issues for TSO packets which use mss as per the new mtu configured. This patch fixes this issue by moving the mtu write after device quiesce. Cc: stable@vger.kernel.org Fixes: d1a890fa37f2 ("net: VMware virtual Ethernet NIC driver: vmxnet3") Signed-off-by: Ronak Doshi Acked-by: Guolin Yang Changes v1-> v2: Moved MTU write after destroy of rx rings Link: https://patch.msgid.link/20250515190457.8597-1-ronak.doshi@broadcom.com Signed-off-by: Jakub Kicinski [ no WRITE_ONCE() in older trees ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/vmxnet3/vmxnet3_drv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 609f65530b9b..a51c4ad9ed20 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -2998,8 +2998,6 @@ vmxnet3_change_mtu(struct net_device *netdev, int new_mtu) struct vmxnet3_adapter *adapter = netdev_priv(netdev); int err = 0; - netdev->mtu = new_mtu; - /* * Reset_work may be in the middle of resetting the device, wait for its * completion. @@ -3013,6 +3011,7 @@ vmxnet3_change_mtu(struct net_device *netdev, int new_mtu) /* we need to re-create the rx queue based on the new mtu */ vmxnet3_rq_destroy_all(adapter); + netdev->mtu = new_mtu; vmxnet3_adjust_rx_ring_size(adapter); err = vmxnet3_rq_create_all(adapter); if (err) { @@ -3029,6 +3028,8 @@ vmxnet3_change_mtu(struct net_device *netdev, int new_mtu) "Closing it\n", err); goto out; } + } else { + netdev->mtu = new_mtu; } out: