[RESEND,v2,0/2] dmaengine: ti: k3-udma: Fix NULL pointer dereference error

Message

Kishon Vijay Abraham I Oct. 27, 2021, 5:56 a.m. UTC

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/[e-mail]

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(-)

Comments

Péter Ujfalusi Oct. 27, 2021, 8:45 a.m. UTC | #1

Hi Kishon,

On 27/10/2021 08:56, Kishon Vijay Abraham I wrote:
> 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.

Nice catch, interesting that it did not materialized before.

Can you re-word the patch subjects and commit messages accordingly?

This is not really BCDMA/PKTDMA issue but a missed uc->Xchan = NULL;
which would cause the de-reference error.

> 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/[e-mail]
> 
> Kishon Vijay Abraham I (2):
>   dmaengine: ti: k3-udma: Fix NULL pointer dereference error for BCDMA

dmaengine: ti: k3-udma: Set bchan to NULL if a channel request fail

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

dmaengine: ti: k3-udma: Set rchan/tchan to NULL if a channel request fail

This is also applicable for UDMA which only have rchan and tchan.

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