CVE-2023-52872: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: fix race condition in status line change on dead connections gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all timers, removing the virtual tty devices and clearing the data queues. This procedure, however, may cause subsequent changes of the virtual modem status lines of a DLCI. More data is being added the outgoing data queue and the deleted kick timer is restarted to handle this. At this point many resources have already been removed by the cleanup procedure. Thus, a kernel panic occurs. Fix this by proving in gsm_modem_update() that the cleanup procedure has not been started and the mux is still alive. Note that writing to a virtual tty is already protected by checks against the DLCI specific connection state.

Business impact

Successful exploitation of CVE-2023-52872, a high vulnerability (CVSS 7.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
• Reference
• Reference
• Reference
• Reference