CVE-2024-42152

/// Technical description

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

nvmet: fix a possible leak when destroy a ctrl during qp establishment

In nvmet_sq_destroy we capture sq->ctrl early and if it is non-NULL we

know that a ctrl was allocated (in the admin connect request handler)

and we need to release pending AERs, clear ctrl->sqs and sq->ctrl

(for nvme-loop primarily), and drop the final reference on the ctrl.

However, a small window is possible where nvmet_sq_destroy starts (as

a result of the client giving up and disconnecting) concurrently with

the nvme admin connect cmd (which may be in an early stage). But *before*

kill_and_confirm of sq->ref (i.e. the admin connect managed to get an sq

live reference). In this case, sq->ctrl was allocated however after it was

captured in a local variable in nvmet_sq_destroy.

This prevented the final reference drop on the ctrl.

Solve this by re-capturing the sq->ctrl after all inflight request has

completed, where for sure sq->ctrl reference

/// 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