Re: [PATCH] media: mediatek: jpeg: Avoid context access after job finish

[Nicolas Dufresne <nicolas@ndufresne.ca>]

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Le mercredi 02 septembre 2026 à 20:22 +0900, Kazuki Hanai a écrit :
> v4l2_m2m_job_finish() publishes job completion and wakes waiters
> before it returns. A concurrent file release can therefore finish
> v4l2_m2m_ctx_release() and free the context while the single-core IRQ
> handler continues with its tail.
> 
> Both handlers only need the device for the matching runtime PM put.
> Use the IRQ-owned jpeg pointer instead of dereferencing ctx after
> completion has been published. This preserves the get/put pairing and
> removes the post-completion context access.
> 
> Fixes: 45f13a57d813 ("media: platform: Add jpeg enc feature")
> Fixes: 5827e4b14ee7 ("media: platform: Improve power on and power off flow")
> Cc: stable@vger.kernel.org
> Assisted-by: Codex:gpt-5
> Signed-off-by: Kazuki Hanai <hnkz.64@gmail.com>

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

> ---
>  drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> index d147ec4830811..9010e7b1108fa 100644
> --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> @@ -1574,7 +1574,7 @@ static irqreturn_t mtk_jpeg_enc_done(struct mtk_jpeg_dev *jpeg)
>  	v4l2_m2m_buf_done(src_buf, buf_state);
>  	v4l2_m2m_buf_done(dst_buf, buf_state);
>  	v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
> -	pm_runtime_put(ctx->jpeg->dev);
> +	pm_runtime_put(jpeg->dev);
>  	return IRQ_HANDLED;
>  }
>  
> @@ -1855,7 +1855,7 @@ static irqreturn_t mtk_jpeg_dec_irq(int irq, void *priv)
>  	v4l2_m2m_buf_done(src_buf, buf_state);
>  	v4l2_m2m_buf_done(dst_buf, buf_state);
>  	v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
> -	pm_runtime_put(ctx->jpeg->dev);
> +	pm_runtime_put(jpeg->dev);
>  	return IRQ_HANDLED;
>  }
>  

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