CVE-2024-26698

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove

In commit ac5047671758 ("hv_netvsc: Disable NAPI before closing the

VMBus channel"), napi_disable was getting called for all channels,

including all subchannels without confirming if they are enabled or not.

This caused hv_netvsc getting hung at napi_disable, when netvsc_probe()

has finished running but nvdev->subchan_work has not started yet.

netvsc_subchan_work() -> rndis_set_subchannel() has not created the

sub-channels and because of that netvsc_sc_open() is not running.

netvsc_remove() calls cancel_work_sync(&nvdev->subchan_work), for which

netvsc_subchan_work did not run.

netif_napi_add() sets the bit NAPI_STATE_SCHED because it ensures NAPI

cannot be scheduled. Then netvsc_sc_open() -> napi_enable will clear the

NAPIF_STATE_SCHED bit, so it can be scheduled. napi_disable() does the

opposite.

Now during netvsc_device_remove(), when napi_dis

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References