CVE-2024-56674

/// Technical description

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

virtio_net: correct netdev_tx_reset_queue() invocation point

When virtnet_close is followed by virtnet_open, some TX completions can

possibly remain unconsumed, until they are finally processed during the

first NAPI poll after the netdev_tx_reset_queue(), resulting in a crash

[1]. Commit b96ed2c97c79 ("virtio_net: move netdev_tx_reset_queue() call

before RX napi enable") was not sufficient to eliminate all BQL crash

cases for virtio-net.

This issue can be reproduced with the latest net-next master by running:

`while :; do ip l set DEV down; ip l set DEV up; done` under heavy network

TX load from inside the machine.

netdev_tx_reset_queue() can actually be dropped from virtnet_open path;

the device is not stopped in any case. For BQL core part, it's just like

traffic nearly ceases to exist for some period. For stall detector added

to BQL, even if virtnet_close could somehow lead to some TX completions

delayed for lon

/// 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