From 11bb6ae21c8117642d4c8615407b3181e0cb9241 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Sun, 8 Nov 2020 23:41:00 +0100 Subject: [PATCH] spi: lpspi: Fix use-after-free on unbind commit 4def49da620c84a682d9361d6bef0a97eed46fe0 upstream. Normally the last reference on an spi_controller is released by spi_unregister_controller(). In the case of the i.MX lpspi driver, the spi_controller is registered with devm_spi_register_controller(), so spi_unregister_controller() is invoked automatically after the driver has unbound. However the driver already releases the last reference in fsl_lpspi_remove() through a gratuitous call to spi_master_put(), causing a use-after-free when spi_unregister_controller() is subsequently invoked by the devres framework. Fix by dropping the superfluous spi_master_put(). Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi") Signed-off-by: Lukas Wunner Cc: # v5.2+ Cc: Han Xu Link: https://lore.kernel.org/r/ab3c0b18bd820501a12c85e440006e09ec0e275f.1604874488.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-fsl-lpspi.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index 92e460d4f3d1..ecb4396707cf 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -973,9 +973,6 @@ static int fsl_lpspi_remove(struct platform_device *pdev) spi_controller_get_devdata(controller); pm_runtime_disable(fsl_lpspi->dev); - - spi_master_put(controller); - return 0; }