spi: pxa2xx: Fix use-after-free on unbind

pxa2xx_spi_remove() accesses the driver's private data after calling
spi_unregister_controller() even though that function releases the last
reference on the spi_controller and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master/slave() helper
which keeps the private data accessible until the driver has unbound.

Fixes: 32e5b57232c0 ("spi: pxa2xx: Fix controller unregister order")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v2.6.17+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: <stable@vger.kernel.org> # v2.6.17+: 32e5b57232c0: spi: pxa2xx: Fix controller unregister order
Cc: <stable@vger.kernel.org> # v2.6.17+
Link: https://lore.kernel.org/r/5764b04d4a6e43069ebb7808f64c2f774ac6f193.1607286887.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 62a0f0f865535aeaf40efe7a019d67ecc50930c1..bd2354fd438d4f52d09c7c010db43f0862720787 100644 (file)
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1691,9 +1691,9 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
        }
 
        if (platform_info->is_slave)
-               controller = spi_alloc_slave(dev, sizeof(struct driver_data));
+               controller = devm_spi_alloc_slave(dev, sizeof(*drv_data));
        else
-               controller = spi_alloc_master(dev, sizeof(struct driver_data));
+               controller = devm_spi_alloc_master(dev, sizeof(*drv_data));
 
        if (!controller) {
                dev_err(&pdev->dev, "cannot alloc spi_controller\n");
@@ -1916,7 +1916,6 @@ out_error_dma_irq_alloc:
        free_irq(ssp->irq, drv_data);
 
 out_error_controller_alloc:
-       spi_controller_put(controller);
        pxa_ssp_free(ssp);
        return status;
 }