spi: spi-axi: fix potential use-after-free after deregistration
[ Upstream commit 4d5e0689dc9d5640ad46cdfbe1896b74d8df1661 ]
Take an extra reference to the controller before deregistering it to
prevent use-after-free in the interrupt handler in case an interrupt
fires before the line is disabled.
Fixes: b1353d1c1d45 ("spi: Add Analog Devices AXI SPI Engine controller support")
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index c1eafbd..da51fed 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -553,7 +553,7 @@
static int spi_engine_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 spi_engine *spi_engine = spi_master_get_devdata(master);
int irq = platform_get_irq(pdev, 0);
@@ -561,6 +561,8 @@
free_irq(irq, master);
+ spi_master_put(master);
+
writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);