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dmaengine: at_hdmac: fix memory leak in at_dma_xlate()

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commit 98f5f932254b88ce828bc8e4d1642d14e5854caa upstream.

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: bbe89c8e3d59 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Richard Genoud 2018-11-27 17:06:34 +01:00 committed by Greg Kroah-Hartman
parent 4e443d70a1
commit 0daa7fc2c5
1 changed files with 7 additions and 1 deletions
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8
drivers/dma/at_hdmac.c
View File

@ -1774,6 +1774,12 @@ 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");
}
@ -1808,7 +1814,7 @@ 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;