The Linux kernel mtk-jpeg driver had a flaw where the mtk_jpeg_release function called cancel_work_sync unconditionally, even for variants without an initialized workqueue callback. This caused WARN_ON prints in the kernel due to failed checks in __flush_work. The fix restricts cancel_work_sync calls to only those variants with a valid workqueue callback, preventing unnecessary kernel warnings.

This issue causes kernel warning messages (WARN_ON) due to improper cancellation of workqueues on unsupported platforms. There is no indication of code execution, privilege escalation, or denial of service beyond these warnings. No known exploits are reported in the wild.

A fix has been implemented in the Linux kernel to conditionally call cancel_work_sync only when a workqueue callback is defined. Users should apply the updated kernel version containing this fix once available. Patch status is not explicitly confirmed; check the vendor or kernel mailing list advisories for the official patch and update guidance.