kernel/linux.git/drivers/media/platform/mediatek, branch v6.18.35

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

2026-05-07T04:11:36+00:00

commit 34c519feef3e4fcff1078dc8bdb25fbbbd10303f upstream. 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. Fixes: 5fb1c2361e56 ("mtk-jpegenc: add jpeg encode worker interface") Cc: stable@vger.kernel.org Signed-off-by: Fan Wu Reviewed-by: Nicolas Dufresne Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman

media: mediatek: vcodec: fix use-after-free in encoder release path

2026-04-22T11:22:32+00:00

commit 76e35091ffc722ba39b303e48bc5d08abb59dd56 upstream. The fops_vcodec_release() function frees the context structure (ctx) without first cancelling any pending or running work in ctx->encode_work. This creates a race window where the workqueue handler (mtk_venc_worker) may still be accessing the context memory after it has been freed. Race condition: CPU 0 (release path) CPU 1 (workqueue) --------------------- ------------------ fops_vcodec_release() v4l2_m2m_ctx_release() v4l2_m2m_cancel_job() // waits for m2m job "done" mtk_venc_worker() v4l2_m2m_job_finish() // m2m job "done" // BUT worker still running! // post-job_finish access: other ctx dereferences // UAF if ctx already freed // returns (job "done") kfree(ctx) // ctx freed Root cause: The v4l2_m2m_ctx_release() only waits for the m2m job lifecycle (via TRANS_RUNNING flag), not the workqueue lifecycle. After v4l2_m2m_job_finish() is called, the m2m framework considers the job complete and v4l2_m2m_ctx_release() returns, but the worker function continues executing and may still access ctx. The work is queued during encode operations via: queue_work(ctx->dev->encode_workqueue, &ctx->encode_work) The worker function accesses ctx->m2m_ctx, ctx->dev, and other ctx fields even after calling v4l2_m2m_job_finish(). This vulnerability was confirmed with KASAN by running an instrumented test module that widens the post-job_finish race window. KASAN detected: BUG: KASAN: slab-use-after-free in mtk_venc_worker+0x159/0x180 Read of size 4 at addr ffff88800326e000 by task kworker/u8:0/12 Workqueue: mtk_vcodec_enc_wq mtk_venc_worker Allocated by task 47: __kasan_kmalloc+0x7f/0x90 fops_vcodec_open+0x85/0x1a0 Freed by task 47: __kasan_slab_free+0x43/0x70 kfree+0xee/0x3a0 fops_vcodec_release+0xb7/0x190 Fix this by calling cancel_work_sync(&ctx->encode_work) before kfree(ctx). This ensures the workqueue handler is both cancelled (if pending) and synchronized (waits for any running handler to complete) before the context is freed. Placement rationale: The fix is placed after v4l2_ctrl_handler_free() and before list_del_init(&ctx->list). At this point, all m2m operations are done (v4l2_m2m_ctx_release() has returned), and we need to ensure the workqueue is synchronized before removing ctx from the list and freeing it. 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 device_run() operations. Fixes: 0934d3759615 ("media: mediatek: vcodec: separate decoder and encoder") Cc: stable@vger.kernel.org Signed-off-by: Fan Wu Reviewed-by: Nicolas Dufresne Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman

media: mtk-mdp: Fix a reference leak bug in mtk_mdp_remove()

2026-03-04T12:20:57+00:00

[ Upstream commit f128bab57b8018e526b7eda854ca20069863af47 ] In mtk_mdp_probe(), vpu_get_plat_device() increases the reference count of the returned platform device. Add platform_device_put() to prevent reference leak. Fixes: c8eb2d7e8202 ("[media] media: Add Mediatek MDP Driver") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin

media: mtk-mdp: Fix error handling in probe function

2026-03-04T12:20:57+00:00

[ Upstream commit 8a8a3232abac5b972058a5f2cb3e33199d2a8648 ] Add mtk_mdp_unregister_m2m_device() on the error handling path to prevent resource leak. Add check for the return value of vpu_get_plat_device() to prevent null pointer dereference. And vpu_get_plat_device() increases the reference count of the returned platform device. Add platform_device_put() to prevent reference leak. Fixes: c8eb2d7e8202 ("[media] media: Add Mediatek MDP Driver") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin

media: mediatek: encoder: Fix uninitialized scalar variable issue

2026-03-04T12:20:56+00:00

[ Upstream commit 88e935de7cf8795d7a6a51385db87ecb361a7050 ] UNINIT checker finds some instances of variables that are used without being initialized, for example using the uninitialized value enc_result.is_key_frm can result in unpredictable behavior, so initialize these variables after declaring. Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver") Cc: stable@vger.kernel.org Signed-off-by: Irui Wang Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin

media: mediatek: vcodec: Don't try to decode 422/444 VP9

2026-03-04T12:19:52+00:00

[ Upstream commit 3e92d7e4935084ecdbdc88880cc4688618ae1557 ] This is not supported by the hardware and trying to decode these leads to LAT timeout errors. Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin

media: mediatek: vcodec: Fix a reference leak in mtk_vcodec_fw_vpu_init()

2026-01-08T09:17:05+00:00

commit cdd0f118ef87db8a664fb5ea366fd1766d2df1cd upstream. vpu_get_plat_device() increases the reference count of the returned platform device. However, when devm_kzalloc() fails, the reference is not released, causing a reference leak. Fix this by calling put_device() on fw_pdev->dev before returning on the error path. Fixes: e25a89f743b1 ("media: mtk-vcodec: potential dereference of null pointer") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Tzung-Bi Shih Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman

media: mediatek: vcodec: Use spinlock for context list protection lock

2026-01-08T09:17:05+00:00

commit a5844227e0f030d2af2d85d4aed10c5eca6ca176 upstream. Previously a mutex was added to protect the encoder and decoder context lists from unexpected changes originating from the SCP IP block, causing the context pointer to go invalid, resulting in a NULL pointer dereference in the IPI handler. Turns out on the MT8173, the VPU IPI handler is called from hard IRQ context. This causes a big warning from the scheduler. This was first reported downstream on the ChromeOS kernels, but is also reproducible on mainline using Fluster with the FFmpeg v4l2m2m decoders. Even though the actual capture format is not supported, the affected code paths are triggered. Since this lock just protects the context list and operations on it are very fast, it should be OK to switch to a spinlock. Fixes: 6467cda18c9f ("media: mediatek: vcodec: adding lock to protect decoder context list") Fixes: afaaf3a0f647 ("media: mediatek: vcodec: adding lock to protect encoder context list") Cc: Yunfei Dong Cc: stable@vger.kernel.org Signed-off-by: Chen-Yu Tsai Reviewed-by: Fei Shao Reviewed-by: Tomasz Figa Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman

media: platform: mtk-mdp3: fix device leaks at probe

2026-01-08T09:17:04+00:00

commit 8f6f3aa21517ef34d50808af0c572e69580dca20 upstream. Make sure to drop the references taken when looking up the subsys devices during probe on probe failure (e.g. probe deferral) and on driver unbind. Similarly, drop the SCP device reference after retrieving its platform data during probe to avoid leaking it. Note that holding a reference to a device does not prevent its driver data from going away. Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver") Cc: stable@vger.kernel.org # 6.1 Cc: Moudy Ho Signed-off-by: Johan Hovold Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman

media: platform: mtk-mdp3: Add missing MT8188 compatible to comp_dt_ids

2025-09-04T08:14:02+00:00

Commit 4a81656c8eaa ("arm64: dts: mediatek: mt8188: Address binding warnings for MDP3 nodes") caused a regression on the MDP functionality when it removed the MT8195 compatibles from the MDP3 nodes, since the MT8188 compatible was not yet listed as a possible MDP component compatible in mdp_comp_dt_ids. This resulted in an empty output bitstream when using the MDP from userspace, as well as the following errors: mtk-mdp3 14001000.dma-controller: Uninit component inner id 4 mtk-mdp3 14001000.dma-controller: mdp_path_ctx_init error 0 mtk-mdp3 14001000.dma-controller: CMDQ sendtask failed: -22 Add the missing compatible to the array to restore functionality. Fixes: 4a81656c8eaa ("arm64: dts: mediatek: mt8188: Address binding warnings for MDP3 nodes") Cc: stable@vger.kernel.org Signed-off-by: Nícolas F. R. A. Prado Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil