CVE-2023-53810

A flaw was identified in the block multi-queue (blk-mq) subsystem of the Linux kernel where the crypto keyslot associated with a block I/O request could be released after upper layers have been notified that the I/O operation completed. Under certain conditions, this could lead to a use-after-free of the crypto keyslot object if a filesystem segment attempts to evict a crypto key while I/O is still effectively using it.

Red Hat Product Security rates this flaw as having a security impact of Moderate because exploiting the race condition requires local system access, high timing precision during key eviction, and the use of filesystem-level encryption with per-file keys. This issue specifically manifests when an authenticated local user triggers asynchronous cryptographic key removals on filesystems utilizing fscrypt inline block encryption. Because default Red Hat Enterprise Linux configurations do not mandate per-file encryption and exploiting the timing window to achieve arbitrary code execution or local privilege escalation is highly complex, the blast radius is predominantly constrained to localized instability or denial of service.

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 don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.