spi: cadence-qspi: fix pointer reference in runtime PM hooks

dev_get_drvdata() gets used to acquire the pointer to cqspi and the SPI
controller. Neither embed the other; this lead to memory corruption.

On a given platform (Mobileye EyeQ5) the memory corruption is hidden
inside cqspi->f_pdata. Also, this uninitialised memory is used as a
mutex (ctlr->bus_lock_mutex) by spi_controller_suspend().

Fixes: 2087e85bb66e ("spi: cadence-quadspi: fix suspend-resume implementations")
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://msgid.link/r/20240222-cdns-qspi-pm-fix-v4-1-6b6af8bcbf59@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index f94e0d370d466e9742261a84a567593b8073f169..0d184d65dce76356cd7fa73b84de6181aae4ed56 100644 (file)
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1930,10 +1930,9 @@ static void cqspi_remove(struct platform_device *pdev)
 static int cqspi_suspend(struct device *dev)
 {
        struct cqspi_st *cqspi = dev_get_drvdata(dev);
-       struct spi_controller *host = dev_get_drvdata(dev);
        int ret;
 
-       ret = spi_controller_suspend(host);
+       ret = spi_controller_suspend(cqspi->host);
        cqspi_controller_enable(cqspi, 0);
 
        clk_disable_unprepare(cqspi->clk);
@@ -1944,7 +1943,6 @@ static int cqspi_suspend(struct device *dev)
 static int cqspi_resume(struct device *dev)
 {
        struct cqspi_st *cqspi = dev_get_drvdata(dev);
-       struct spi_controller *host = dev_get_drvdata(dev);
 
        clk_prepare_enable(cqspi->clk);
        cqspi_wait_idle(cqspi);
@@ -1953,7 +1951,7 @@ static int cqspi_resume(struct device *dev)
        cqspi->current_cs = -1;
        cqspi->sclk = 0;
 
-       return spi_controller_resume(host);
+       return spi_controller_resume(cqspi->host);
 }
 
 static DEFINE_RUNTIME_DEV_PM_OPS(cqspi_dev_pm_ops, cqspi_suspend,