Re: [PATCH 1/3] media: nxp: imx-jpeg: cancel task_timer before freeing ctx

On Tue, Aug 25, 2026 at 03:34:30AM +0800, Shengzhuo Wei wrote:
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> 

Hi Shengzhuo,

Thanks for the patch.

This use-after-free has already been fixed by Fan Wu:
    https://lore.kernel.org/lkml/[email protected]/
    [PATCH] media: imx-jpeg: cancel timeout worker when streaming stops

Regards,
Ming

> mxc_jpeg_device_run() arms ctx->task_timer for each job; the only place
> it is cancelled is the job-completion IRQ handler. If the hardware
> never completes the job, mxc_jpeg_release() frees ctx with the timer
> still pending, and mxc_jpeg_device_run_timeout() then dereferences the
> freed ctx -- a use-after-free.
> 
> Cancel the timer before the ctx is torn down, before taking
> mxc_jpeg->lock so the cancel never waits on a worker that needs the
> mutex.
> 
> Fixes: cfed9632ca8e ("media: imx-jpeg: Add a timeout mechanism for each frame")
> Cc: [email protected]
> Signed-off-by: Shengzhuo Wei <[email protected]>
> Assisted-by: GLM:5.3
> ---
>  drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
> index 725e941528848e8f224fe6a96ba7f746fc45ed63..fbb64a1ecb5189d2d7b953b99dcd7bcb54e6e20e 100644
> --- a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
> +++ b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
> @@ -2796,6 +2796,8 @@ static int mxc_jpeg_release(struct file *file)
>         struct mxc_jpeg_ctx *ctx = mxc_jpeg_file_to_ctx(file);
>         struct device *dev = mxc_jpeg->dev;
> 
> +       cancel_delayed_work_sync(&ctx->task_timer);
> +
>         mutex_lock(&mxc_jpeg->lock);
>         if (mxc_jpeg->mode == MXC_JPEG_DECODE)
>                 dev_dbg(dev, "Release JPEG decoder instance on slot %d.",
> 
> --
> 2.47.3
>