Commit dd6e4943 authored by Johan Hovold's avatar Johan Hovold Committed by Vinod Koul
Browse files

dmaengine: stm32: dmamux: fix device leak on route allocation 



Make sure to drop the reference taken when looking up the DMA mux
platform device during route allocation.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Fixes: df7e762d ("dmaengine: Add STM32 DMAMUX driver")
Cc: stable@vger.kernel.org	# 4.15
Cc: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Reviewed-by: default avatarAmelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://patch.msgid.link/20251117161258.10679-11-johan@kernel.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 9fb49032

drivers/dma/stm32/stm32-dmamux.c

+12 −6
Original line number Diff line number Diff line
@@ -90,23 +90,25 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, 
	struct stm32_dmamux_data *dmamux = platform_get_drvdata(pdev);

	struct stm32_dmamux *mux;

	u32 i, min, max;

	int ret;

	int ret = -EINVAL;

	unsigned long flags;



	if (dma_spec->args_count != 3) {

		dev_err(&pdev->dev, "invalid number of dma mux args\n");

		return ERR_PTR(-EINVAL);

		goto err_put_pdev;

	}



	if (dma_spec->args[0] > dmamux->dmamux_requests) {

		dev_err(&pdev->dev, "invalid mux request number: %d\n",

			dma_spec->args[0]);

		return ERR_PTR(-EINVAL);

		goto err_put_pdev;

	}



	mux = kzalloc(sizeof(*mux), GFP_KERNEL);

	if (!mux)

		return ERR_PTR(-ENOMEM);

	if (!mux) {

		ret = -ENOMEM;

		goto err_put_pdev;

	}



	spin_lock_irqsave(&dmamux->lock, flags);

	mux->chan_id = find_first_zero_bit(dmamux->dma_inuse,
@@ -133,7 +135,6 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, 
	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", i - 1);

	if (!dma_spec->np) {

		dev_err(&pdev->dev, "can't get dma master\n");

		ret = -EINVAL;

		goto error;

	}
@@ -160,6 +161,8 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, 
	dev_dbg(&pdev->dev, "Mapping DMAMUX(%u) to DMA%u(%u)\n",

		mux->request, mux->master, mux->chan_id);



	put_device(&pdev->dev);



	return mux;



error:
@@ -167,6 +170,9 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, 


error_chan_id:

	kfree(mux);

err_put_pdev:

	put_device(&pdev->dev);



	return ERR_PTR(ret);

}