dmaengine: at_hdmac: fix memory leak in at_dma_xlate()

commit 98f5f93225 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: bbe89c8e3d ("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 2a9443a935
commit 7e572222d3

View file

@ -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;