CVE-2023-53116

A flaw was found in the Linux kernel's NVMe (Non-Volatile Memory Express) target subsystem. During request completion, a memory structure can be prematurely freed and subsequently dereferenced, leading to a use-after-free condition. A local user could exploit this flaw to cause a kernel crash, resulting in a denial of service (DoS).

A moderate use-after-free vulnerability was found in the Linux kernel's NVMe target (nvmet) subsystem, affecting Red Hat Enterprise Linux 9 (kernel and kernel-rt). During request completion, an NVMe target ->queue_response() implementation may free the request passed as its argument, and the request pointer can then be dereferenced when percpu_ref_put() is called in nvmet_req_complete(), resulting in a use-after-free. A local user could exploit this flaw to cause a kernel crash, resulting in a denial of service. Red Hat has rated this flaw Moderate severity (CVSS:3.1 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) because exploitation requires local access with privileges and the impact is limited to availability. The higher NIST (7.8) and CVE.org (9.8) scores assume a broader impact than the technical evidence supports: the CVE.org score assumes a network attack vector requiring no privileges, and the NIST score assumes full confidentiality and integrity impact, while this flaw can only be triggered locally by a privileged user and results in denial of service only. For the affected Red Hat Enterprise Linux 9 streams, the fix is deferred and will be delivered in a future update; the residual risk until then is that a local user could cause a kernel crash (denial of service). Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, and Red Hat In-Vehicle OS are not affected because the vulnerable code is not present in those releases. The Red Hat Enterprise Linux 7 and Red Hat Enterprise Linux 8 records, and the Hosted OpenShift Cluster records, are out of support scope.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.