Commit 98f5f932 authored Nov 27, 2018 by Richard Genoud Committed by Vinod Koul Nov 29, 2018

dmaengine: at_hdmac: fix memory leak in at_dma_xlate()



The leak was found when opening/closing a serial port a great number of
time, increasing kmalloc-32 in slabinfo.

Each time the port was opened, dma_request_slave_channel() was called.
Then, in at_dma_xlate(), atslave was allocated with devm_kzalloc() and
never freed. (Well, it was free at module unload, but that's not what we
want).
So, here, kzalloc is more suited for the job since it has to be freed in
atc_free_chan_resources().

Cc: stable@vger.kernel.org
Fixes: bbe89c8e ("at_hdmac: move to generic DMA binding")
Reported-by: Mario Forner <m.forner@be4energy.com>
Suggested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

parent 65102238

drivers/dma/at_hdmac.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -1641,6 +1641,12 @@ static void atc_free_chan_resources(struct dma_chan *chan)
		atchan->descs_allocated = 0;
		atchan->status = 0;

		/*
		* Free atslave allocated in at_dma_xlate()
		*/
		kfree(chan->private);
		chan->private = NULL;

		dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
		}

		@@ -1675,7 +1681,7 @@ static struct dma_chan at_dma_xlate(struct of_phandle_args dma_spec,
		dma_cap_zero(mask);
		dma_cap_set(DMA_SLAVE, mask);

		atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL);
		atslave = kzalloc(sizeof(*atslave), GFP_KERNEL);
		if (!atslave)
		return NULL;

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