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 <[email protected]>
---
drivers/dma/ti/k3-udma.c | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)
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);
}
--
2.17.1
Hi Peter,
On 09/02/21 5:53 pm, Péter Ujfalusi wrote:
> Hi Kishon,
>
> On 2/9/21 11:00 AM, 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.
>
> I think this can happen when a channel request fails and we get a second
> request coming and faces with the not cleanup up tchan/rchan/bchan/rflow
> from the previous failure.
> Interesting that I have not faced with this, but it is a valid oversight
> from me.
Thank you for reviewing.
Got into this issue when all the PCIe endpoint functions were requesting
for a MEMCOPY channel (total 22 endpoint functions) specifically in
bcdma_get_bchan() where the scenario you mentioned above happened.
Vignesh asked me to fix it for all udma_get_*().
>
>> 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")
>
> Will this patch apply at any of these?
> 25dcb5dd7b7c does not have BCDMA (bchan)
> 017794739702 does not contain PKTDMA (tflow)
I can probably split this patch
017794739702 for bchan and 25dcb5dd7b7c for bchan/rchan/tchan/rflow
>
>> Signed-off-by: Kishon Vijay Abraham I <[email protected]>
>> ---
>> drivers/dma/ti/k3-udma.c | 30 +++++++++++++++++++++++++-----
>> 1 file changed, 25 insertions(+), 5 deletions(-)
>>
>> 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);
>
> return 0;
Will fix this.
Thanks
Kishon
Hi Kishon,
On 2/9/21 2:45 PM, Kishon Vijay Abraham I wrote:
> Hi Peter,
>
> On 09/02/21 5:53 pm, Péter Ujfalusi wrote:
>> Hi Kishon,
>>
>> On 2/9/21 11:00 AM, 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.
>>
>> I think this can happen when a channel request fails and we get a second
>> request coming and faces with the not cleanup up tchan/rchan/bchan/rflow
>> from the previous failure.
>> Interesting that I have not faced with this, but it is a valid oversight
>> from me.
>
> Thank you for reviewing.
>
> Got into this issue when all the PCIe endpoint functions were requesting
> for a MEMCOPY channel (total 22 endpoint functions) specifically in
> bcdma_get_bchan() where the scenario you mentioned above happened.
I see, do we even have 22 bchan allocated for Linux out from the 40? ;)
> Vignesh asked me to fix it for all udma_get_*().
Yes, that is the right thing to do, thank you!
>>
>>> 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")
>>
>> Will this patch apply at any of these?
>> 25dcb5dd7b7c does not have BCDMA (bchan)
>> 017794739702 does not contain PKTDMA (tflow)
>
> I can probably split this patch
> 017794739702 for bchan and 25dcb5dd7b7c for bchan/rchan/tchan/rflow
the tflow support for PKTDMA makes the tchan fix a bit problematic for
backporting, but it might worth a try to split to bcdma and
rchan/tchan/rflow patch.
--
Péter
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 <[email protected]>
Is this the same patch as the other with the similar subject?
--
Péter
> ---
> drivers/dma/ti/k3-udma.c | 30 +++++++++++++++++++++++++-----
> 1 file changed, 25 insertions(+), 5 deletions(-)
>
> 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);
> }
>
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 <[email protected]>
>
> 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