[PATCH v2 2/2] spi: fsl-lpspi: fix missing RX DMA termination on TX prepare failure

[Carlos Song (OSS)]

From: Carlos Song <carlos.song@xxxxxxx>

When dmaengine_prep_slave_sg() fails for the TX channel, the error path
only terminates the TX DMA channel but leaves the RX channel running.
Since the RX channel was already submitted and issued prior to preparing
the TX descriptor, returning -EINVAL causes the SPI core to unmap the
DMA buffers while the RX DMA engine continues writing to them, leading
to potential memory corruption or use-after-free.

Fix this by also terminating the RX channel before returning on the TX
prepare failure path.

Fixes: 09c04466ce7e ("spi: lpspi: add dma mode support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Carlos Song <carlos.song@xxxxxxx>
---
change for v2:
  - Add fix missing RX DMA termination on TX prepare failure.
---
 drivers/spi/spi-fsl-lpspi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 1a94a42fac31..906892453a84 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -647,6 +647,7 @@ static int fsl_lpspi_dma_transfer(struct spi_controller *controller,
 				tx->sgl, tx->nents, DMA_MEM_TO_DEV,
 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc_tx) {
+		dmaengine_terminate_sync(controller->dma_rx);
 		dmaengine_terminate_sync(controller->dma_tx);
 		return -EINVAL;
 	}
-- 
2.43.0