From d710f43ce30975d197f73c543bfe47b958d8ba17 Mon Sep 17 00:00:00 2001 From: Fan Wu Date: Sun, 19 Jul 2026 01:00:13 +0000 Subject: [PATCH] spi: oc-tiny: switch to managed controller allocation The controller is allocated with the non-managed spi_alloc_host() while the interrupt is registered with devm_request_irq(). During removal, spi_bitbang_stop() only unregisters the controller; the subsequent spi_controller_put() then frees the controller together with its embedded driver-private devdata, which is the IRQ handler's dev_id. The devm_request_irq() release action (free_irq()), which drains the handler, does not run until after .remove() returns. A late or latched interrupt can therefore reach tiny_spi_irq() and dereference already-freed memory (e.g. hw->base). Switch to devm_spi_alloc_host() so that the devres LIFO order releases the controller only after free_irq() has drained the handler, and drop the now-redundant spi_controller_put() from .remove(). The probe error path is simplified to direct returns. This issue was found by an in-house static analysis tool. Fixes: ce792580ea2c ("spi: add OpenCores tiny SPI driver") Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu Link: https://patch.msgid.link/20260719010014.3163356-1-fanwu01@zju.edu.cn Signed-off-by: Mark Brown --- drivers/spi/spi-oc-tiny.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/drivers/spi/spi-oc-tiny.c b/drivers/spi/spi-oc-tiny.c index 29333b1f82d7..1cd2a934c032 100644 --- a/drivers/spi/spi-oc-tiny.c +++ b/drivers/spi/spi-oc-tiny.c @@ -210,11 +210,11 @@ static int tiny_spi_probe(struct platform_device *pdev) struct tiny_spi_platform_data *platp = dev_get_platdata(&pdev->dev); struct tiny_spi *hw; struct spi_controller *host; - int err = -ENODEV; + int err; - host = spi_alloc_host(&pdev->dev, sizeof(struct tiny_spi)); + host = devm_spi_alloc_host(&pdev->dev, sizeof(struct tiny_spi)); if (!host) - return err; + return -ENOMEM; /* setup the host state. */ host->bus_num = pdev->id; @@ -232,10 +232,8 @@ static int tiny_spi_probe(struct platform_device *pdev) /* find and map our resources */ hw->base = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(hw->base)) { - err = PTR_ERR(hw->base); - goto exit; - } + if (IS_ERR(hw->base)) + return PTR_ERR(hw->base); /* irq is optional */ hw->irq = platform_get_irq(pdev, 0); if (hw->irq >= 0) { @@ -243,7 +241,7 @@ static int tiny_spi_probe(struct platform_device *pdev) err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0, pdev->name, hw); if (err) - goto exit; + return err; } /* find platform data */ if (platp) { @@ -252,29 +250,23 @@ static int tiny_spi_probe(struct platform_device *pdev) } else { err = tiny_spi_of_probe(pdev); if (err) - goto exit; + return err; } /* register our spi controller */ err = spi_bitbang_start(&hw->bitbang); if (err) - goto exit; + return err; dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq); return 0; - -exit: - spi_controller_put(host); - return err; } static void tiny_spi_remove(struct platform_device *pdev) { struct tiny_spi *hw = platform_get_drvdata(pdev); - struct spi_controller *host = hw->bitbang.ctlr; spi_bitbang_stop(&hw->bitbang); - spi_controller_put(host); } #ifdef CONFIG_OF