iio: light: gp2ap020a00f: drain irq_work after free_irq

Overview

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

iio: light: gp2ap020a00f: drain irq_work after free_irq

The threaded IRQ handler queues data->work through irq_work_queue() so the trigger is polled from a per-CPU context. free_irq() does not flush an irq_work the handler already queued, so after gp2ap020a00f_remove() returns that work may still run and call iio_trigger_poll() on data->trig, which the devm cleanup has already freed, causing a use-after-free.

Add irq_work_sync(&data->work) after free_irq() in remove() and in the probe error path, mirroring commit 78601726d4a5 ("iio: trigger: sysfs: fix use-after-free on remove").

Found by an in-house static analysis tool, confirmed by manual review.

Affected

• Linux >= bf29fbeaa13d3350ca71df70c705d8b883c45692 < a36814b9fe00970116d30c3143d81e7425c4d334
• Linux >= bf29fbeaa13d3350ca71df70c705d8b883c45692 < cc71400bc965c0d3894a38ead3d71243400c2d5e
• Linux >= bf29fbeaa13d3350ca71df70c705d8b883c45692 < a1769877ff52a4f1bfb9ca535d1b5113808bd602
• Linux >= bf29fbeaa13d3350ca71df70c705d8b883c45692 < 63213927b141085b6c8719b8037dab3074b7e0fe
• Linux 3.13

Remediation

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