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authorMarc Kleine-Budde <mkl@pengutronix.de>2022-07-19 10:22:35 +0300
committerMark Brown <broonie@kernel.org>2022-07-20 16:03:40 +0300
commit4ceaa684459d414992acbefb4e4c31f2dfc50641 (patch)
tree54a3e19fbfdcd51783efbc64c39e5d11642e8bef /drivers/spi/spi-bcm2835.c
parent73d5fe046270281a46344e06bf986c607632f7ea (diff)
downloadlinux-4ceaa684459d414992acbefb4e4c31f2dfc50641.tar.xz
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 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>
Diffstat (limited to 'drivers/spi/spi-bcm2835.c')
-rw-r--r--drivers/spi/spi-bcm2835.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 775c0bf2f923..0933948d7df3 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 */