The mtk_jpeg_release function in the Linux kernel driver invokes cancel_work_sync unconditionally, even for variants of the driver that do not use a workqueue. When the workqueue callback pointer is NULL, cancel_work_sync calls __flush_work, which triggers a WARN_ON in __flush_work. This results in a kernel warning for any release of the driver that lacks a workqueue callback.

This issue affects the Linux kernel’s media subsystem, specifically the mtk-jpeg driver on multicore-based platforms that employ a workqueue. The warning is triggered even on platforms that do not use the workqueue, as the function call is unconditional. No specific kernel version or configuration is listed, so any kernel with the affected driver implementation may be impacted.

The EPSS score is below 1% and the vulnerability is not listed in the CISA KEV catalog, indicating a low likelihood of exploitation. Because the flaw leads only to a kernel warning rather than a controllable attack vector, the security impact is minimal. The risk is predominantly operational rather than known attack path exists beyond the unconditional call made during driver release.