The Linux kernel's accel/qaic component did not properly handle QAIC_TRANS_DEACTIVATE_FROM_DEV transactions if the owning user process went away before deactivation was processed. This caused the host to become out-of-sync with available DBCs, leaving resources allocated and leading to indefinite waits when the same DBC was reassigned, causing user processes to hang. The issue was fixed by improving handling of deactivation transactions received after the user process has terminated. This vulnerability affects multiple Linux kernel versions prior to 6.8.0-1064.72~22.04.1 and related builds. The CVSS 3.1 score is 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), reflecting local attack vector with low complexity, requiring privileges, no user interaction, and high impact on confidentiality, integrity, and availability. A patch is available as per Ubuntu security advisories USN-8567-1 and USN-8574-1.

Exploitation of this vulnerability can cause indefinite hangs of user processes due to resource mismanagement in the QAIC DBC handling. This leads to denial of service conditions and potential disruption of network activation requests. The vulnerability impacts confidentiality, integrity, and availability as indicated by the CVSS score, though exploitation requires local privileges and access to the affected subsystem.

A patch is available and should be applied by updating the Linux kernel to versions at or beyond the fixed releases (e.g., 6.8.0-1064.72~22.04.1 or later). After applying the update, a system reboot is required to complete remediation. Due to an ABI change in the kernel update, recompilation and reinstallation of third-party kernel modules may be necessary. Follow the vendor's official Ubuntu security advisories USN-8567-1 and USN-8574-1 for detailed update instructions.