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spi: bcm2835: bcm2835_spi_handle_err(): fix NULL pointer deref for non DMA transfers 

commit 4ceaa68445 upstream.

In case a IRQ based transfer times out the bcm2835_spi_handle_err()
function is called. Since commit 1513ceee70 ("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: 1513ceee70 ("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>
This commit is contained in:
Marc Kleine-Budde 2022-07-19 09:22:35 +02:00 committed by Greg Kroah-Hartman
parent 4c728788a7
commit 49ffa47321
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/spi/spi-bcm2835.c
View File

@ -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 */