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hv_netvsc: fix race of netvsc and VF register_netdevice

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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: e04e7a7bbd ("hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()")
Reported-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Haiyang Zhang 2023-11-19 08:23:41 -08:00 committed by Paolo Abeni
parent c0e2926266
commit d30fb712e5
1 changed files with 16 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/net/hyperv/netvsc_drv.c
View File

@ -2531,6 +2531,21 @@ static int netvsc_probe(struct hv_device *dev,
goto devinfo_failed;
}
/* 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
* netvsc_probe() can't get rtnl lock and as a result vmbus_onoffer()
* -> ... -> 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);
@ -2540,16 +2555,6 @@ static int netvsc_probe(struct hv_device *dev,
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
* netvsc_probe() can't get rtnl lock and as a result vmbus_onoffer()
* -> ... -> device_add() -> ... -> __device_attach() can't get
* the device lock, so all the subchannels can't be processed --
* finally netvsc_subchan_work() hangs forever.
*/
rtnl_lock();
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);