CVE-2026-46011

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

media: mtk-jpeg: fix use-after-free in release path due to uncancelled work

The mtk_jpeg_release() function frees the context structure (ctx) without first cancelling any pending or running work in ctx->jpeg_work. This creates a race window where the workqueue callback may still be accessing the context memory after it has been freed.

Race condition:

CPU 0 (release)                    CPU 1 (workqueue)
----------------                   ------------------
close()
  mtk_jpeg_release()
                                   mtk_jpegenc_worker()
                                     ctx = work->data
                                     // accessing ctx

    kfree(ctx)  // freed!
                                     access ctx  // UAF!

The work is queued via queue_work() during JPEG encode/decode operations (via mtk_jpeg_device_run). If the device is closed while work is pending or running, the work handler will access freed memory.

Fix this by calling cancel_work_sync() BEFORE acquiring the mutex. This ordering is critical: if cancel_work_sync() is called after mutex_lock(), and the work handler also tries to acquire the same mutex, it would cause a deadlock.

Note: The open error path does NOT need cancel_work_sync() because INIT_WORK() only initializes the work structure - it does not schedule it. Work is only scheduled later during ioctl operations.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/0498b27a1542021d90269d58347501d4c3ccd84e
• https://git.kernel.org/stable/c/2209fdae5c2f615930c9af1379c1cfca199ec5d8
• https://git.kernel.org/stable/c/26506a30e0e26d612f82a7bf0e395626968a44e6
• https://git.kernel.org/stable/c/34c519feef3e4fcff1078dc8bdb25fbbbd10303f
• https://git.kernel.org/stable/c/e78c39f720679fcf3a2eacd82725ec3ea2648301