* [PATCH net,v3, 1/2] hv_netvsc: Fix race of netvsc and VF register_netdevice
[not found] <1699391132-30317-1-git-send-email-haiyangz@microsoft.com>
@ 2023-11-07 21:05 ` Haiyang Zhang
2023-11-07 21:05 ` [PATCH net,v3, 2/2] hv_netvsc: Fix race of register_netdevice_notifier and VF register Haiyang Zhang
1 sibling, 0 replies; 4+ messages in thread
From: Haiyang Zhang @ 2023-11-07 21:05 UTC (permalink / raw)
To: linux-hyperv, netdev
Cc: haiyangz, kys, wei.liu, decui, edumazet, kuba, pabeni, davem,
linux-kernel, stable
The rtnl lock also needs to be held before rndis_filter_device_add()
which advertises nvsp_2_vsc_capability / sriov bit, and triggers
VF NIC offering and registering. If VF NIC finished register_netdev()
earlier it may cause name based config failure.
To fix this issue, move the call to rtnl_lock() before
rndis_filter_device_add(), so VF will be registered later than netvsc
/ synthetic NIC, and gets a name numbered (ethX) after netvsc.
Cc: stable@vger.kernel.org
Fixes: e04e7a7bbd4b ("hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
---
v3:
Divide it into two patches, suggested by Jakub Kicinski.
v2:
Fix rtnl_unlock() in error handling as found by Wojciech Drewek.
---
drivers/net/hyperv/netvsc_drv.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 3ba3c8fb28a5..5e528a76f5f5 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2531,15 +2531,6 @@ static int netvsc_probe(struct hv_device *dev,
goto devinfo_failed;
}
- nvdev = rndis_filter_device_add(dev, device_info);
- if (IS_ERR(nvdev)) {
- ret = PTR_ERR(nvdev);
- netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
- goto rndis_failed;
- }
-
- eth_hw_addr_set(net, device_info->mac_adr);
-
/* We must get rtnl lock before scheduling nvdev->subchan_work,
* otherwise netvsc_subchan_work() can get rtnl lock first and wait
* all subchannels to show up, but that may not happen because
@@ -2547,9 +2538,23 @@ static int netvsc_probe(struct hv_device *dev,
* -> ... -> device_add() -> ... -> __device_attach() can't get
* the device lock, so all the subchannels can't be processed --
* finally netvsc_subchan_work() hangs forever.
+ *
+ * The rtnl lock also needs to be held before rndis_filter_device_add()
+ * which advertises nvsp_2_vsc_capability / sriov bit, and triggers
+ * VF NIC offering and registering. If VF NIC finished register_netdev()
+ * earlier it may cause name based config failure.
*/
rtnl_lock();
+ nvdev = rndis_filter_device_add(dev, device_info);
+ if (IS_ERR(nvdev)) {
+ ret = PTR_ERR(nvdev);
+ netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
+ goto rndis_failed;
+ }
+
+ eth_hw_addr_set(net, device_info->mac_adr);
+
if (nvdev->num_chn > 1)
schedule_work(&nvdev->subchan_work);
@@ -2586,9 +2591,9 @@ static int netvsc_probe(struct hv_device *dev,
return 0;
register_failed:
- rtnl_unlock();
rndis_filter_device_remove(dev, nvdev);
rndis_failed:
+ rtnl_unlock();
netvsc_devinfo_put(device_info);
devinfo_failed:
free_percpu(net_device_ctx->vf_stats);
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH net,v3, 2/2] hv_netvsc: Fix race of register_netdevice_notifier and VF register
[not found] <1699391132-30317-1-git-send-email-haiyangz@microsoft.com>
2023-11-07 21:05 ` [PATCH net,v3, 1/2] hv_netvsc: Fix race of netvsc and VF register_netdevice Haiyang Zhang
@ 2023-11-07 21:05 ` Haiyang Zhang
2023-11-09 2:26 ` Jakub Kicinski
1 sibling, 1 reply; 4+ messages in thread
From: Haiyang Zhang @ 2023-11-07 21:05 UTC (permalink / raw)
To: linux-hyperv, netdev
Cc: haiyangz, kys, wei.liu, decui, edumazet, kuba, pabeni, davem,
linux-kernel, stable
If VF NIC is registered earlier, NETDEV_REGISTER event is replayed,
but NETDEV_POST_INIT is not.
Move register_netdevice_notifier() earlier, so the call back
function is set before probing.
Cc: stable@vger.kernel.org
Fixes: e04e7a7bbd4b ("hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
---
v3:
Divide it into two patches, suggested by Jakub Kicinski.
v2:
Fix rtnl_unlock() in error handling as found by Wojciech Drewek.
---
drivers/net/hyperv/netvsc_drv.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 5e528a76f5f5..1d1491da303b 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2793,11 +2793,14 @@ static int __init netvsc_drv_init(void)
}
netvsc_ring_bytes = ring_size * PAGE_SIZE;
+ register_netdevice_notifier(&netvsc_netdev_notifier);
+
ret = vmbus_driver_register(&netvsc_drv);
- if (ret)
+ if (ret) {
+ unregister_netdevice_notifier(&netvsc_netdev_notifier);
return ret;
+ }
- register_netdevice_notifier(&netvsc_netdev_notifier);
return 0;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread