CVE-2024-42152: nvmet: fix a possible leak when destroy a ctrl during qp establishment

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-30 · updated 2026-08-04
Weakness: CWE-401

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 is final, and move forward based on that. This issue was observed in an environment with many hosts connecting multiple ctrls simoutanuosly, creating a delay in allocating a ctrl leading up to this race window.

Affected products

Linux kernel: from 4.8 before 5.10.222; from 5.11 before 5.15.163; from 5.16 before 6.1.98; from 6.2 before 6.6.39; from 6.7 before 6.9.9; 6.10-rc1 — fixed in 5.10.222, 5.15.163, 6.1.98, 6.6.39, 6.9.9

How to fix

Upgrade to a fixed version: Linux kernel 5.10.222, 5.15.163, 6.1.98, 6.6.39. Check the vendor advisory for mitigations.

References

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