From: Marc Kleine-Budde mkl@pengutronix.de
commit 4ceaa684459d414992acbefb4e4c31f2dfc50641 upstream.
In case a IRQ based transfer times out the bcm2835_spi_handle_err() function is called. Since commit 1513ceee70f2 ("spi: bcm2835: Drop dma_pending flag") the TX and RX DMA transfers are unconditionally canceled, leading to NULL pointer derefs if ctlr->dma_tx or ctlr->dma_rx are not set.
Fix the NULL pointer deref by checking that ctlr->dma_tx and ctlr->dma_rx are valid pointers before accessing them.
Fixes: 1513ceee70f2 ("spi: bcm2835: Drop dma_pending flag") Cc: Lukas Wunner lukas@wunner.de Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Link: https://lore.kernel.org/r/20220719072234.2782764-1-mkl@pengutronix.de Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/spi/spi-bcm2835.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
--- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1138,10 +1138,14 @@ static void bcm2835_spi_handle_err(struc struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
/* if an error occurred and we have an active dma, then terminate */ - dmaengine_terminate_sync(ctlr->dma_tx); - bs->tx_dma_active = false; - dmaengine_terminate_sync(ctlr->dma_rx); - bs->rx_dma_active = false; + if (ctlr->dma_tx) { + dmaengine_terminate_sync(ctlr->dma_tx); + bs->tx_dma_active = false; + } + if (ctlr->dma_rx) { + dmaengine_terminate_sync(ctlr->dma_rx); + bs->rx_dma_active = false; + } bcm2835_spi_undo_prologue(bs);
/* and reset */