CVE-2026-90193

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A self-deadlock occurs in the IRQ handler of the qcom-cpucp mailbox. The function qcom cpucp mbox irq fn() calls mbox chan received data() while holding chan->lock. In PREEMPT RT configurations, spin lock irqsave() is converted to an rt spinlock (a mutex-based lock that tracks ownership and can sleep). The subsequent callback chain leads to mailbox clear channel(), mbox send message(), and finally add to rbuf(), which attempts to re-acquire chan->lock. Because the rtmutex detects a re-entrant lock attempt by the same owner, the thread blocks indefinitely, resulting in a permanent deadlock where the process remains stuck in D state.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.