Commit eb91224e authored by Kishon Vijay Abraham I's avatar Kishon Vijay Abraham I Committed by Vinod Koul
Browse files

dmaengine: ti: k3-udma: Set r/tchan or rflow to NULL if request fail 



udma_get_*() checks if rchan/tchan/rflow is already allocated by checking
if it has a NON NULL value. For the error cases, rchan/tchan/rflow will
have error value and udma_get_*() considers this as already allocated
(PASS) since the error values are NON NULL. This results in NULL pointer
dereference error while de-referencing rchan/tchan/rflow.

Reset the value of rchan/tchan/rflow to NULL if a channel request fails.

CC: stable@vger.kernel.org
Acked-by: default avatarPeter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20211031032411.27235-3-kishon@ti.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 5c6c6d60

drivers/dma/ti/k3-udma.c

+20 −4
Original line number Diff line number Diff line
@@ -1380,6 +1380,7 @@ static int bcdma_get_bchan(struct udma_chan *uc) 
static int udma_get_tchan(struct udma_chan *uc)

{

	struct udma_dev *ud = uc->ud;

	int ret;



	if (uc->tchan) {

		dev_dbg(ud->dev, "chan%d: already have tchan%d allocated\n",
@@ -1394,8 +1395,11 @@ static int udma_get_tchan(struct udma_chan *uc) 
	 */

	uc->tchan = __udma_reserve_tchan(ud, uc->config.channel_tpl,

					 uc->config.mapped_channel_id);

	if (IS_ERR(uc->tchan))

		return PTR_ERR(uc->tchan);

	if (IS_ERR(uc->tchan)) {

		ret = PTR_ERR(uc->tchan);

		uc->tchan = NULL;

		return ret;

	}



	if (ud->tflow_cnt) {

		int tflow_id;
@@ -1425,6 +1429,7 @@ static int udma_get_tchan(struct udma_chan *uc) 
static int udma_get_rchan(struct udma_chan *uc)

{

	struct udma_dev *ud = uc->ud;

	int ret;



	if (uc->rchan) {

		dev_dbg(ud->dev, "chan%d: already have rchan%d allocated\n",
@@ -1439,8 +1444,13 @@ static int udma_get_rchan(struct udma_chan *uc) 
	 */

	uc->rchan = __udma_reserve_rchan(ud, uc->config.channel_tpl,

					 uc->config.mapped_channel_id);

	if (IS_ERR(uc->rchan)) {

		ret = PTR_ERR(uc->rchan);

		uc->rchan = NULL;

		return ret;

	}



	return PTR_ERR_OR_ZERO(uc->rchan);

	return 0;

}



static int udma_get_chan_pair(struct udma_chan *uc)
@@ -1494,6 +1504,7 @@ static int udma_get_chan_pair(struct udma_chan *uc) 
static int udma_get_rflow(struct udma_chan *uc, int flow_id)

{

	struct udma_dev *ud = uc->ud;

	int ret;



	if (!uc->rchan) {

		dev_err(ud->dev, "chan%d: does not have rchan??\n", uc->id);
@@ -1507,8 +1518,13 @@ static int udma_get_rflow(struct udma_chan *uc, int flow_id) 
	}



	uc->rflow = __udma_get_rflow(ud, flow_id);

	if (IS_ERR(uc->rflow)) {

		ret = PTR_ERR(uc->rflow);

		uc->rflow = NULL;

		return ret;

	}



	return PTR_ERR_OR_ZERO(uc->rflow);

	return 0;

}



static void bcdma_put_bchan(struct udma_chan *uc)