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

PATCH Superseded Kishon Vijay Abraham I 1 participant 6 messages Oct 27, 2021

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Kishon Vijay Abraham I

author

2021-10-27 05:53 UTC #0 lore raw

PATCH v2 1/2 dmaengine: ti: k3-udma: Fix NULL pointer dereference error for BCDMA

bcdma_get_*() checks if bchan is already allocated by checking if it has a NON NULL value. For the error cases, bchan will have error value and bcdma_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.

Reset the value of bchan to NULL if the allocation actually fails.

Signed-off-by Kishon Vijay Abraham I <[email protected]>

---
 drivers/dma/ti/k3-udma.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

drivers/dma/ti/k3-udma.c +6 -2

index a35858610780..14ae28830871 100644
@@ -1348,6 +1348,7 @@ 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",

@@ -1365,8 +1366,11 @@ 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;

Signature · 1 line

2.17.1

Kishon Vijay Abraham I

author

2021-10-27 05:53 UTC #1 lore raw

PATCH v2 1/2 dmaengine: ti: k3-udma: Fix NULL pointer dereference error for BCDMA

Reset the value of bchan to NULL if the allocation actually fails.

Signed-off-by Kishon Vijay Abraham I <[email protected]>

---
 drivers/dma/ti/k3-udma.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

drivers/dma/ti/k3-udma.c +6 -2

index a35858610780..14ae28830871 100644
@@ -1348,6 +1348,7 @@ 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",

@@ -1365,8 +1366,11 @@ 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;

Signature · 1 line

2.17.1

Kishon Vijay Abraham I

author

2021-10-27 05:53 UTC #2 lore raw

v2 cover dmaengine: ti: k3-udma: Fix NULL pointer dereference error

In reply to Kishon Vijay Abraham I

NULL pointer de-reference error was observed when all the PCIe endpoint functions (22 function in J721E) request a DMA channel. The issue was specfically observed in BCDMA (Block copy DMA) but the issue is applicable in PKTDMA as well.

Changes from v1:
1) Split the patch for BCDMA and PKTDMA separately
2) Fixed the return value of udma_get_rflow() to 0.
3) Removed the fixes tag as the patches does not directly apply to the commits.

v1 => https://lore.kernel.org/r/[email protected]

Kishon Vijay Abraham I (2):
dmaengine: ti: k3-udma: Fix NULL pointer dereference error for BCDMA
dmaengine: ti: k3-udma: Fix NULL pointer dereference error for PKTDMA

 drivers/dma/ti/k3-udma.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

Signature · 1 line

2.17.1

Kishon Vijay Abraham I

author

2021-10-27 05:53 UTC #3 lore raw

PATCH v2 2/2 dmaengine: ti: k3-udma: Fix NULL pointer dereference error for PKTDMA

In reply to Kishon Vijay Abraham I

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 the allocation actually fails.

Signed-off-by Kishon Vijay Abraham I <[email protected]>

---
 drivers/dma/ti/k3-udma.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

drivers/dma/ti/k3-udma.c +20 -4

index 14ae28830871..041d8e32d630 100644
@@ -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)

Signature · 1 line

2.17.1

Kishon Vijay Abraham I

author

2021-10-27 06:00 UTC #4 lore raw

PATCH v2 2/2 dmaengine: ti: k3-udma: Fix NULL pointer dereference error for PKTDMA

In reply to Kishon Vijay Abraham I

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

Signed-off-by Kishon Vijay Abraham I <[email protected]>

---
 drivers/dma/ti/k3-udma.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

drivers/dma/ti/k3-udma.c +20 -4

index 14ae28830871..041d8e32d630 100644
@@ -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)

Signature · 1 line

2.17.1

Kishon Vijay Abraham I

author

2021-10-27 06:00 UTC #5 lore raw

In reply to Kishon Vijay Abraham I

Hi All,

Quoted 9 lines · Kishon Vijay Abraham I

bcdma_get_*() checks if bchan is already allocated by checking if it has a NON NULL value. For the error cases, bchan will have error value and bcdma_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.
Reset the value of bchan to NULL if the allocation actually fails.
Signed-off-by Kishon Vijay Abraham I <[email protected]>

Please ignore this series. There was some stray patches left which I failed to notice before sending. I'll resend a clean one.

Thanks,
Kishon

Quoted 31 lines

---
 drivers/dma/ti/k3-udma.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

drivers/dma/ti/k3-udma.c +6 -2

index a35858610780..14ae28830871 100644
@@ -1348,6 +1348,7 @@ 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",

@@ -1365,8 +1366,11 @@ 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;