4.19-stable review patch. If anyone has any objections, please let me know.
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From: Richard Genoud richard.genoud@gmail.com
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
--- drivers/dma/at_hdmac.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1641,6 +1641,12 @@ static void atc_free_chan_resources(stru 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(str 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;