[PATCH 6.6 007/143] spi: cadence-qspi: fix pointer reference in runtime PM hooks

Greg Kroah-Hartman
2024-03-04T21:36:59Z

From: Théo Lebrun <theo.lebrun@bootlin.com>

[ Upstream commit 32ce3bb57b6b402de2aec1012511e7ac4e7449dc ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-cadence-quadspi.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 2064dc4ea935f..08811577d8f8b 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1904,10 +1904,9 @@ 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);
@@ -1918,7 +1917,6 @@ 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);
@@ -1927,7 +1925,7 @@ 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_SIMPLE_DEV_PM_OPS(cqspi_dev_pm_ops, cqspi_suspend, cqspi_resume);
--
2.43.0