Re: [PATCH] ASoC: fsl_asrc_dma: Fix dma_chan leak when config DMA channel failed

[Mark Brown]

On Mon, 25 May 2020 22:12:46 +0800, Xiyu Yang wrote:
> fsl_asrc_dma_hw_params() invokes dma_request_channel() or
> fsl_asrc_get_dma_channel(), which returns a reference of the specified
> dma_chan object to "pair->dma_chan[dir]" with increased refcnt.
> 
> The reference counting issue happens in one exception handling path of
> fsl_asrc_dma_hw_params(). When config DMA channel failed for Back-End,
> the function forgets to decrease the refcnt increased by
> dma_request_channel() or fsl_asrc_get_dma_channel(), causing a refcnt
> leak.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl_asrc_dma: Fix dma_chan leak when config DMA channel failed
  commit: 36124fb19f1ae68a500cd76a76d40c6e81bee346

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
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Thanks,
Mark

[PATCH] ASoC: fsl_asrc_dma: Fix dma_chan leak when config DMA channel failed

[Xiyu Yang]

fsl_asrc_dma_hw_params() invokes dma_request_channel() or
fsl_asrc_get_dma_channel(), which returns a reference of the specified
dma_chan object to "pair->dma_chan[dir]" with increased refcnt.

The reference counting issue happens in one exception handling path of
fsl_asrc_dma_hw_params(). When config DMA channel failed for Back-End,
the function forgets to decrease the refcnt increased by
dma_request_channel() or fsl_asrc_get_dma_channel(), causing a refcnt
leak.

Fix this issue by calling dma_release_channel() when config DMA channel
failed.

Signed-off-by: Xiyu Yang 
Signed-off-by: Xin Tan 
---
 sound/soc/fsl/fsl_asrc_dma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index e7178817d7a7..1ee10eafe3e6 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -252,6 +252,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component 
*component,
ret = dmaengine_slave_config(pair->dma_chan[dir], _be);
if (ret) {
dev_err(dev, "failed to config DMA channel for Back-End\n");
+   dma_release_channel(pair->dma_chan[dir]);
return ret;
}
 
-- 
2.7.4