spi/mpc512x-psc: Avoid access to freed memory in device remove function
authorGuenter Roeck <linux@roeck-us.net>
Sat, 18 Aug 2012 16:29:24 +0000 (09:29 -0700)
committerMark Brown <broonie@opensource.wolfsonmicro.com>
Wed, 22 Aug 2012 18:26:36 +0000 (19:26 +0100)
The call to spi_unregister_master() in the device remove function frees device
memory, and with it any device local data. However, device local data is still
accessed after the call to spi_unregister_master().

Acquire a reference to the SPI master device and release it after cleanup is
complete to solve the problem.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
drivers/spi/spi-mpc512x-psc.c

index 4c63f77..0a1e39e 100644 (file)
@@ -494,7 +494,7 @@ free_master:
 
 static int __devexit mpc512x_psc_spi_do_remove(struct device *dev)
 {
-       struct spi_master *master = dev_get_drvdata(dev);
+       struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
        struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
 
        flush_workqueue(mps->workqueue);
@@ -503,6 +503,7 @@ static int __devexit mpc512x_psc_spi_do_remove(struct device *dev)
        free_irq(mps->irq, mps);
        if (mps->psc)
                iounmap(mps->psc);
+       spi_master_put(master);
 
        return 0;
 }