diff mbox series

dmaengine: ti: k3-udma: Fix NULL pointer dereference error

Message ID 20210209120238.9476-1-kishon@ti.com (mailing list archive)
State Not Applicable
Headers show
Series dmaengine: ti: k3-udma: Fix NULL pointer dereference error | expand

Commit Message

Kishon Vijay Abraham I Feb. 9, 2021, 12:02 p.m. UTC 
bcdma_get_*() and udma_get_*() checks if bchan/rchan/tchan/rflow is
already allocated by checking if it has a NON NULL value. For the
error cases, bchan/rchan/tchan/rflow will have error value
and bcdma_get_*() 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
bchan/rchan/tchan/rflow.

Reset the value of bchan/rchan/tchan/rflow to NULL if the allocation
actually fails.

Fixes: 017794739702 ("dmaengine: ti: k3-udma: Initial support for K3 BCDMA")
Fixes: 25dcb5dd7b7c ("dmaengine: ti: New driver for K3 UDMA")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/dma/ti/k3-udma.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

Comments

Péter Ujfalusi Feb. 10, 2021, 10:03 a.m. UTC | #1 
Hi Kishon,

On 2/9/21 2:02 PM, Kishon Vijay Abraham I wrote:
> bcdma_get_*() and udma_get_*() checks if bchan/rchan/tchan/rflow is
> already allocated by checking if it has a NON NULL value. For the
> error cases, bchan/rchan/tchan/rflow will have error value
> and bcdma_get_*() 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
> bchan/rchan/tchan/rflow.
> 
> Reset the value of bchan/rchan/tchan/rflow to NULL if the allocation
> actually fails.
> 
> Fixes: 017794739702 ("dmaengine: ti: k3-udma: Initial support for K3 BCDMA")
> Fixes: 25dcb5dd7b7c ("dmaengine: ti: New driver for K3 UDMA")
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Is this the same patch as the other with the similar subject?
Kishon Vijay Abraham I Feb. 10, 2021, 11:34 a.m. UTC | #2 
Hi Peter,

On 10/02/21 3:33 pm, Péter Ujfalusi wrote:
> Hi Kishon,
> 
> On 2/9/21 2:02 PM, Kishon Vijay Abraham I wrote:
>> bcdma_get_*() and udma_get_*() checks if bchan/rchan/tchan/rflow is
>> already allocated by checking if it has a NON NULL value. For the
>> error cases, bchan/rchan/tchan/rflow will have error value
>> and bcdma_get_*() 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
>> bchan/rchan/tchan/rflow.
>>
>> Reset the value of bchan/rchan/tchan/rflow to NULL if the allocation
>> actually fails.
>>
>> Fixes: 017794739702 ("dmaengine: ti: k3-udma: Initial support for K3 BCDMA")
>> Fixes: 25dcb5dd7b7c ("dmaengine: ti: New driver for K3 UDMA")
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> 
> Is this the same patch as the other with the similar subject?

Right, sorry for the duplicate patch (thought it didn't go out initially).

Regards
Kishon
diff mbox series

Patch

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 298460438bb4..aa4ef583ff83 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -1330,6 +1330,7 @@  static int bcdma_get_bchan(struct udma_chan *uc)
 {
 	struct udma_dev *ud = uc->ud;
 	enum udma_tp_level tpl;
+	int ret;
 
 	if (uc->bchan) {
 		dev_dbg(ud->dev, "chan%d: already have bchan%d allocated\n",
@@ -1347,8 +1348,11 @@  static int bcdma_get_bchan(struct udma_chan *uc)
 		tpl = ud->bchan_tpl.levels - 1;
 
 	uc->bchan = __udma_reserve_bchan(ud, tpl, -1);
-	if (IS_ERR(uc->bchan))
-		return PTR_ERR(uc->bchan);
+	if (IS_ERR(uc->bchan)) {
+		ret = PTR_ERR(uc->bchan);
+		uc->bchan = NULL;
+		return ret;
+	}
 
 	uc->tchan = uc->bchan;
 
@@ -1358,6 +1362,7 @@  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",
@@ -1372,8 +1377,11 @@  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;
@@ -1403,6 +1411,7 @@  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",
@@ -1417,8 +1426,13 @@  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)
@@ -1472,6 +1486,7 @@  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);
@@ -1485,6 +1500,11 @@  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);
 }