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 when using mem-to-mem copy.
Changes from v3:
1) Fix commit subject
2) Add "Acked-by: Peter Ujfalusi <[email protected]>" and cc'ed
stable
Changes from v2:
1) Fix commit subject and commit log to mention bchan/rchan/tchan to NULL
suggested by Peter.
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]
v2 => https://lore.kernel.org/r/[email protected]
v3 => https://lore.kernel.org/r/[email protected]
Kishon Vijay Abraham I (2):
dmaengine: ti: k3-udma: Set bchan to NULL if a channel request fail
dmaengine: ti: k3-udma: Set r/tchan or rflow to NULL if request fail
drivers/dma/ti/k3-udma.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
--
2.17.1
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: [email protected]
Acked-by: Peter Ujfalusi <[email protected]>
Signed-off-by: Kishon Vijay Abraham I <[email protected]>
---
drivers/dma/ti/k3-udma.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 14ae28830871..041d8e32d630 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -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)
--
2.17.1
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 a channel request fails.
CC: [email protected]
Acked-by: Peter Ujfalusi <[email protected]>
Signed-off-by: Kishon Vijay Abraham I <[email protected]>
---
drivers/dma/ti/k3-udma.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index a35858610780..14ae28830871 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -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;
--
2.17.1