spi: stm32: fix potential dereference null return value

This patch fixes the usage of rx_dma_desc and tx_dma_desc pointers
returned by dmaengine_prep_slave_sg, which can be null.

Detected by CoverityScan, CID#1446587 ("Dereference null return value")

Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Amelie Delaunay 2017-06-27 17:45:20 +02:00 committed by Mark Brown
parent c67ad368cf
commit 7b821a6485

View file

@ -775,9 +775,6 @@ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
xfer->rx_sg.nents,
rx_dma_conf.direction,
DMA_PREP_INTERRUPT);
rx_dma_desc->callback = stm32_spi_dma_cb;
rx_dma_desc->callback_param = spi;
}
tx_dma_desc = NULL;
@ -790,11 +787,6 @@ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
xfer->tx_sg.nents,
tx_dma_conf.direction,
DMA_PREP_INTERRUPT);
if (spi->cur_comm == SPI_SIMPLEX_TX) {
tx_dma_desc->callback = stm32_spi_dma_cb;
tx_dma_desc->callback_param = spi;
}
}
if ((spi->tx_buf && !tx_dma_desc) ||
@ -802,6 +794,9 @@ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
goto dma_desc_error;
if (rx_dma_desc) {
rx_dma_desc->callback = stm32_spi_dma_cb;
rx_dma_desc->callback_param = spi;
if (dma_submit_error(dmaengine_submit(rx_dma_desc))) {
dev_err(spi->dev, "Rx DMA submit failed\n");
goto dma_desc_error;
@ -811,6 +806,11 @@ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
}
if (tx_dma_desc) {
if (spi->cur_comm == SPI_SIMPLEX_TX) {
tx_dma_desc->callback = stm32_spi_dma_cb;
tx_dma_desc->callback_param = spi;
}
if (dma_submit_error(dmaengine_submit(tx_dma_desc))) {
dev_err(spi->dev, "Tx DMA submit failed\n");
goto dma_submit_error;