spi: fsl-dspi: fix use-after-free in remove path

spi_unregister_controller() not only unregisters the controller, but
also frees the controller. This will free the driver data with it, so
we must not access it later dspi_remove().

Solve this by allocating the driver data separately from the SPI
controller.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20200923131026.20707-1-s.hauer@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Sascha Hauer 2020-09-23 15:10:26 +02:00 committed by Mark Brown
parent b867eef4cf
commit 530b5affc6
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@ -1273,11 +1273,14 @@ static int dspi_probe(struct platform_device *pdev)
void __iomem *base;
bool big_endian;
ctlr = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
dspi = devm_kzalloc(&pdev->dev, sizeof(*dspi), GFP_KERNEL);
if (!dspi)
return -ENOMEM;
ctlr = spi_alloc_master(&pdev->dev, 0);
if (!ctlr)
return -ENOMEM;
dspi = spi_controller_get_devdata(ctlr);
dspi->pdev = pdev;
dspi->ctlr = ctlr;
@ -1414,7 +1417,7 @@ poll_mode:
if (dspi->devtype_data->trans_mode != DSPI_DMA_MODE)
ctlr->ptp_sts_supported = true;
platform_set_drvdata(pdev, ctlr);
platform_set_drvdata(pdev, dspi);
ret = spi_register_controller(ctlr);
if (ret != 0) {
@ -1437,8 +1440,7 @@ out_ctlr_put:
static int dspi_remove(struct platform_device *pdev)
{
struct spi_controller *ctlr = platform_get_drvdata(pdev);
struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);
struct fsl_dspi *dspi = platform_get_drvdata(pdev);
/* Disconnect from the SPI framework */
spi_unregister_controller(dspi->ctlr);