CVE-2026-90193
kernel: mailbox: qcom-cpucp: fix PREEMPT_RT self-deadlock in IRQ handler
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 17, 2026
Updated · October 13, 2026
Description
A flaw was found in the Linux kernel's qcom-cpucp mailbox driver. Under specific PREEMPT_RT configurations, the qcom_cpucp_mbox_irq_fn() interrupt handler attempts to re-acquire a spinlock it already holds. This re-entrant lock attempt causes a permanent deadlock within the kernel. This can lead to a system hang, resulting in a Denial of Service (DoS).
CVSS score applicability
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
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-833 · Deadlock