spi: tegra20-slink: fix UAF in tegra_slink_remove()

[ Upstream commit 7e9984d183 ]

After calling spi_unregister_master(), the refcount of master will
be decrease to 0, and it will be freed in spi_controller_release(),
the device data also will be freed, so it will lead a UAF when using
'tspi'. To fix this, get the master before unregister and put it when
finish using it.

Fixes: 26c8634182 ("spi: tegra20-slink: Don't use resource-managed spi_register helper")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220713094024.1508869-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yang Yingliang 2022-07-13 17:40:23 +08:00 committed by Greg Kroah-Hartman
parent 34bab623eb
commit 800c7767e0

View file

@ -1137,7 +1137,7 @@ static int tegra_slink_probe(struct platform_device *pdev)
static int tegra_slink_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
spi_unregister_master(master);
@ -1152,6 +1152,7 @@ static int tegra_slink_remove(struct platform_device *pdev)
if (tspi->rx_dma_chan)
tegra_slink_deinit_dma_param(tspi, true);
spi_master_put(master);
return 0;
}