From: Marc Kleine-Budde Date: Tue, 19 Jul 2022 07:22:35 +0000 (+0200) Subject: spi: bcm2835: bcm2835_spi_handle_err(): fix NULL pointer deref for non DMA transfers X-Git-Tag: baikal/mips/sdk6.1~5268^2~2 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=4929a17f9b021b2fc736ba7d9fabc0ef1822fa80;p=kernel.git spi: bcm2835: bcm2835_spi_handle_err(): fix NULL pointer deref for non DMA transfers In case a IRQ based transfer times out the bcm2835_spi_handle_err() function is called. Since commit d2ad94bb88af ("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: d2ad94bb88af ("spi: bcm2835: Drop dma_pending flag") Cc: Lukas Wunner Signed-off-by: Marc Kleine-Budde Link: https://lore.kernel.org/r/20220719072234.2782764-1-mkl@pengutronix.de Signed-off-by: Mark Brown --- diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 775c0bf2f923d..0933948d7df3d 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1138,10 +1138,14 @@ static void bcm2835_spi_handle_err(struct spi_controller *ctlr, 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 */