Oracle Linux: CVE-2023-31084: ELSA-2023-12688: Unbreakable Enterprise kernel security update (IMPORTANT) (Multiple Advisories)

An issue was discovered in drivers/media/dvb-core/dvb_frontend.c in the Linux kernel 6.2. There is a blocking operation when a task is in !TASK_RUNNING. In dvb_frontend_get_event, wait_event_interruptible is called; the condition is dvb_frontend_test_event(fepriv,events). In dvb_frontend_test_event, down(&fepriv->sem) is called. However, wait_event_interruptible would put the process to sleep, and down(&fepriv->sem) may block the process.
A potential deadlock flaw was found in the Linux’s kernel DVB API (used by Digital TV devices) functionality. This flaw allows a local user to crash the system.