spi: cadence-quadspi: Remove spi_master_put() in probe failure path

Currently the spi_master is allocated by devm_spi_alloc_master()
and devres core manages the deallocation, but in probe failure
path spi_master_put() is being handled manually which causes
"refcount underflow use-after-free" warning when probe failure happens
after allocating spi_master.

Trimmed backtrace during failure:

refcount_t: underflow; use-after-free.
pc : refcount_warn_saturate+0xf4/0x144
Call trace:
refcount_warn_saturate
kobject_put
put_device
devm_spi_release_controller
devres_release_all

This commit makes relevant changes to remove spi_master_put() from probe
failure path.

Fixes: 606e5d408184 ("spi: cadence-quadspi: Handle spi_unregister_master() in remove()")

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Link: https://lore.kernel.org/r/20220601071611.11853-1-vaishnav.a@ti.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 2b9fc84..72b1a5a 100644 (file)
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1578,8 +1578,7 @@ static int cqspi_probe(struct platform_device *pdev)
        ret = cqspi_of_get_pdata(cqspi);
        if (ret) {
                dev_err(dev, "Cannot get mandatory OF data.\n");
-               ret = -ENODEV;
-               goto probe_master_put;
+               return -ENODEV;
        }
 
        /* Obtain QSPI clock. */
@@ -1587,7 +1586,7 @@ static int cqspi_probe(struct platform_device *pdev)
        if (IS_ERR(cqspi->clk)) {
                dev_err(dev, "Cannot claim QSPI clock.\n");
                ret = PTR_ERR(cqspi->clk);
-               goto probe_master_put;
+               return ret;
        }
 
        /* Obtain and remap controller address. */
@@ -1596,7 +1595,7 @@ static int cqspi_probe(struct platform_device *pdev)
        if (IS_ERR(cqspi->iobase)) {
                dev_err(dev, "Cannot remap controller address.\n");
                ret = PTR_ERR(cqspi->iobase);
-               goto probe_master_put;
+               return ret;
        }
 
        /* Obtain and remap AHB address. */
@@ -1605,7 +1604,7 @@ static int cqspi_probe(struct platform_device *pdev)
        if (IS_ERR(cqspi->ahb_base)) {
                dev_err(dev, "Cannot remap AHB address.\n");
                ret = PTR_ERR(cqspi->ahb_base);
-               goto probe_master_put;
+               return ret;
        }
        cqspi->mmap_phys_base = (dma_addr_t)res_ahb->start;
        cqspi->ahb_size = resource_size(res_ahb);
@@ -1614,15 +1613,13 @@ static int cqspi_probe(struct platform_device *pdev)
 
        /* Obtain IRQ line. */
        irq = platform_get_irq(pdev, 0);
-       if (irq < 0) {
-               ret = -ENXIO;
-               goto probe_master_put;
-       }
+       if (irq < 0)
+               return -ENXIO;
 
        pm_runtime_enable(dev);
        ret = pm_runtime_resume_and_get(dev);
        if (ret < 0)
-               goto probe_master_put;
+               return ret;
 
        ret = clk_prepare_enable(cqspi->clk);
        if (ret) {
@@ -1716,8 +1713,6 @@ probe_reset_failed:
 probe_clk_failed:
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);
-probe_master_put:
-       spi_master_put(master);
        return ret;
 }