In the Linux kernel, the following vulnerability has been resolved: virtio: rtc: time out alarm requests RTC class operations run with rtc_device.ops_lock held

Overview

In the Linux kernel, the following vulnerability has been resolved:

virtio: rtc: time out alarm requests

RTC class operations run with rtc_device.ops_lock held. The virtio RTC alarm requests currently wait without a timeout for the device to return their requestq buffers.

On surprise removal, virtio-pci marks the virtqueues broken before unregistering the virtio device. If an alarm request is waiting when the device stops responding, viortc_remove() blocks in viortc_class_stop() while trying to acquire ops_lock. The request cannot complete and device removal hangs until the waiting task is signalled.

Use the same 60-second timeout as clock read requests for alarm reads, alarm programming, and alarm interrupt enable requests. The existing message reference counting keeps a timed-out request alive until a late response or device teardown.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.