From: Yang Yingliang yangyingliang@huawei.com
[ Upstream commit 7e9984d183bb1e99e766c5c2b950ff21f7f7b6c0 ]
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: 26c863418221 ("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 --- drivers/spi/spi-tegra20-slink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c index 38360434d6e9..148043d0c2b8 100644 --- a/drivers/spi/spi-tegra20-slink.c +++ b/drivers/spi/spi-tegra20-slink.c @@ -1136,7 +1136,7 @@ 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); @@ -1151,6 +1151,7 @@ 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; }