4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Richard Genoud <[email protected]> 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: [email protected] Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Reported-by: Mario Forner <[email protected]> Suggested-by: Alexandre Belloni <[email protected]> Acked-by: Alexandre Belloni <[email protected]> Acked-by: Ludovic Desroches <[email protected]> Signed-off-by: Richard Genoud <[email protected]> Signed-off-by: Vinod Koul <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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 @@ -1774,6 +1774,12 @@ 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"); } @@ -1808,7 +1814,7 @@ 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;
