[SRU] [B] [PATCH 0/2] Fix NULL pointer dereference in netvsc_probe()

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1814069

[Impact]
NULL pointer dereference in netvsc_probe(). Module hv_netvsc is included
in initramfs, so this blocks the boot process.

For Hyper-V only supports single channel, rndis_filter_device_add()
bails early and jump to tag "out". Subsequent code calls
rndis_filter_device_remove() and returns ERR_PTR(ret), where ret is
0 (sucess). Because of that, it passes IS_ERR(nvdev) check in
netvsc_probe() and cause a NULL pointer dereference, as nvdev now is 0:

...
        if (nvdev->num_chn > 1)
                schedule_work(&nvdev->subchan_work);

[Fix]
Correctly return net_device at the end of rndis_filter_device_add().

[Test]
Users report positive result.

[Regression Potenial]
Low. Trivial change, patches are in upstream sometime.

Stephen Hemminger (1):
  hv/netvsc: fix handling of fallback to single queue mode

Takashi Iwai (1):
  hv/netvsc: Fix NULL dereference at single queue mode fallback

 drivers/net/hyperv/rndis_filter.c | 1 +
 1 file changed, 1 insertion(+)

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2.17.1