From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Genoud Subject: [PATCH] dmaengine: at_hdmac: fix memory leak in at_dma_xlate() Date: Tue, 27 Nov 2018 17:06:34 +0100 Message-ID: <20181127160635.11836-1-richard.genoud@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: stable-owner@vger.kernel.org To: Ludovic Desroches , Dan Williams , Vinod Koul Cc: Alexandre Belloni , Nicolas Ferre , Maxime Ripard , Mario Forner , linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Richard Genoud , stable@vger.kernel.org List-Id: linux-serial@vger.kernel.org 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 Suggested-by: Alexandre Belloni Acked-by: Alexandre Belloni Signed-off-by: Richard Genoud --- drivers/dma/at_hdmac.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 7cbac6e8c113..1b7f0ca0d5cd 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -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;