From ef3d549e1deb3466c61f3b01d22fc3fe3e5efb08 Mon Sep 17 00:00:00 2001 From: Felix Gu Date: Thu, 19 Mar 2026 00:12:34 +0800 Subject: [PATCH 1/6] spi: sn-f-ospi: Fix resource leak in f_ospi_probe() In f_ospi_probe(), when num_cs validation fails, it returns without calling spi_controller_put() on the SPI controller, which causes a resource leak. Use devm_spi_alloc_host() instead of spi_alloc_host() to ensure the SPI controller is properly freed when probe fails. Fixes: 1b74dd64c861 ("spi: Add Socionext F_OSPI SPI flash controller driver") Signed-off-by: Felix Gu Link: https://patch.msgid.link/20260319-sn-f-v1-1-33a6738d2da8@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-sn-f-ospi.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/drivers/spi/spi-sn-f-ospi.c b/drivers/spi/spi-sn-f-ospi.c index bfcc140df810..1f554aa7ca27 100644 --- a/drivers/spi/spi-sn-f-ospi.c +++ b/drivers/spi/spi-sn-f-ospi.c @@ -612,7 +612,7 @@ static int f_ospi_probe(struct platform_device *pdev) u32 num_cs = OSPI_NUM_CS; int ret; - ctlr = spi_alloc_host(dev, sizeof(*ospi)); + ctlr = devm_spi_alloc_host(dev, sizeof(*ospi)); if (!ctlr) return -ENOMEM; @@ -635,16 +635,12 @@ static int f_ospi_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ospi); ospi->base = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(ospi->base)) { - ret = PTR_ERR(ospi->base); - goto err_put_ctlr; - } + if (IS_ERR(ospi->base)) + return PTR_ERR(ospi->base); ospi->clk = devm_clk_get_enabled(dev, NULL); - if (IS_ERR(ospi->clk)) { - ret = PTR_ERR(ospi->clk); - goto err_put_ctlr; - } + if (IS_ERR(ospi->clk)) + return PTR_ERR(ospi->clk); mutex_init(&ospi->mlock); @@ -661,9 +657,6 @@ static int f_ospi_probe(struct platform_device *pdev) err_destroy_mutex: mutex_destroy(&ospi->mlock); -err_put_ctlr: - spi_controller_put(ctlr); - return ret; } From a42c9b8b0c00ecd9b7467844f2fbfc766898bf54 Mon Sep 17 00:00:00 2001 From: Felix Gu Date: Thu, 19 Mar 2026 00:12:35 +0800 Subject: [PATCH 2/6] spi: sn-f-ospi: Use devm_mutex_init() to simplify code Switch to devm_mutex_init() to handle mutex destruction automatically. This simplifies the error paths in probe() and removes the need for an explicit mutex_destroy() in remove() callback. Signed-off-by: Felix Gu Link: https://patch.msgid.link/20260319-sn-f-v1-2-33a6738d2da8@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-sn-f-ospi.c | 25 +++++-------------------- 1 file changed, 5 insertions(+), 20 deletions(-) diff --git a/drivers/spi/spi-sn-f-ospi.c b/drivers/spi/spi-sn-f-ospi.c index 1f554aa7ca27..3c61c799723b 100644 --- a/drivers/spi/spi-sn-f-ospi.c +++ b/drivers/spi/spi-sn-f-ospi.c @@ -642,29 +642,15 @@ static int f_ospi_probe(struct platform_device *pdev) if (IS_ERR(ospi->clk)) return PTR_ERR(ospi->clk); - mutex_init(&ospi->mlock); + ret = devm_mutex_init(dev, &ospi->mlock); + if (ret) + return ret; ret = f_ospi_init(ospi); if (ret) - goto err_destroy_mutex; + return ret; - ret = devm_spi_register_controller(dev, ctlr); - if (ret) - goto err_destroy_mutex; - - return 0; - -err_destroy_mutex: - mutex_destroy(&ospi->mlock); - - return ret; -} - -static void f_ospi_remove(struct platform_device *pdev) -{ - struct f_ospi *ospi = platform_get_drvdata(pdev); - - mutex_destroy(&ospi->mlock); + return devm_spi_register_controller(dev, ctlr); } static const struct of_device_id f_ospi_dt_ids[] = { @@ -679,7 +665,6 @@ static struct platform_driver f_ospi_driver = { .of_match_table = f_ospi_dt_ids, }, .probe = f_ospi_probe, - .remove = f_ospi_remove, }; module_platform_driver(f_ospi_driver); From 63542bb402b7013171c9f621c28b609eda4dbf1f Mon Sep 17 00:00:00 2001 From: Felix Gu Date: Sun, 22 Mar 2026 21:29:56 +0800 Subject: [PATCH 3/6] spi: meson-spicc: Fix double-put in remove path meson_spicc_probe() registers the controller with devm_spi_register_controller(), so teardown already drops the controller reference via devm cleanup. Calling spi_controller_put() again in meson_spicc_remove() causes a double-put. Fixes: 8311ee2164c5 ("spi: meson-spicc: fix memory leak in meson_spicc_remove") Signed-off-by: Felix Gu Reviewed-by: Johan Hovold Link: https://patch.msgid.link/20260322-rockchip-v1-1-fac3f0c6dad8@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-meson-spicc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c index a7001b9e36e6..57768da3205d 100644 --- a/drivers/spi/spi-meson-spicc.c +++ b/drivers/spi/spi-meson-spicc.c @@ -1101,8 +1101,6 @@ static void meson_spicc_remove(struct platform_device *pdev) /* Disable SPI */ writel(0, spicc->base + SPICC_CONREG); - - spi_controller_put(spicc->host); } static const struct meson_spicc_data meson_spicc_gx_data = { From cc34d77dd48708d810c12bfd6f5bf03304f6c824 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Tue, 24 Mar 2026 01:59:15 +0100 Subject: [PATCH 4/6] spi: use generic driver_override infrastructure When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Also note that we do not enable the driver_override feature of struct bus_type, as SPI - in contrast to most other buses - passes "" to sysfs_emit() when the driver_override pointer is NULL. Thus, printing "\n" instead of "(null)\n". Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 5039563e7c25 ("spi: Add driver_override SPI device attribute") Signed-off-by: Danilo Krummrich Link: https://patch.msgid.link/20260324005919.2408620-12-dakr@kernel.org Signed-off-by: Mark Brown --- drivers/spi/spi.c | 19 +++++++------------ include/linux/spi/spi.h | 5 ----- 2 files changed, 7 insertions(+), 17 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 53dee314d76a..4101c2803eb3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -50,7 +50,6 @@ static void spidev_release(struct device *dev) struct spi_device *spi = to_spi_device(dev); spi_controller_put(spi->controller); - kfree(spi->driver_override); free_percpu(spi->pcpu_statistics); kfree(spi); } @@ -73,10 +72,9 @@ static ssize_t driver_override_store(struct device *dev, struct device_attribute *a, const char *buf, size_t count) { - struct spi_device *spi = to_spi_device(dev); int ret; - ret = driver_set_override(dev, &spi->driver_override, buf, count); + ret = __device_set_driver_override(dev, buf, count); if (ret) return ret; @@ -86,13 +84,8 @@ static ssize_t driver_override_store(struct device *dev, static ssize_t driver_override_show(struct device *dev, struct device_attribute *a, char *buf) { - const struct spi_device *spi = to_spi_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", spi->driver_override ? : ""); - device_unlock(dev); - return len; + guard(spinlock)(&dev->driver_override.lock); + return sysfs_emit(buf, "%s\n", dev->driver_override.name ?: ""); } static DEVICE_ATTR_RW(driver_override); @@ -376,10 +369,12 @@ static int spi_match_device(struct device *dev, const struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); const struct spi_driver *sdrv = to_spi_driver(drv); + int ret; /* Check override first, and if set, only use the named driver */ - if (spi->driver_override) - return strcmp(spi->driver_override, drv->name) == 0; + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Attempt an OF style match */ if (of_driver_match_device(dev, drv)) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index af7cfee7b8f6..0dc671c07d3a 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -159,10 +159,6 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * @modalias: Name of the driver to use with this device, or an alias * for that name. This appears in the sysfs "modalias" attribute * for driver coldplugging, and in uevents used for hotplugging - * @driver_override: If the name of a driver is written to this attribute, then - * the device will bind to the named driver and only the named driver. - * Do not set directly, because core frees it; use driver_set_override() to - * set or clear it. * @pcpu_statistics: statistics for the spi_device * @word_delay: delay to be inserted between consecutive * words of a transfer @@ -224,7 +220,6 @@ struct spi_device { void *controller_state; void *controller_data; char modalias[SPI_NAME_SIZE]; - const char *driver_override; /* The statistics */ struct spi_statistics __percpu *pcpu_statistics; From 8d2e0cb3224c89275c5471c92850e7f74df80c20 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 25 Mar 2026 15:53:19 +0100 Subject: [PATCH 5/6] spi: fix use-after-free on managed registration failure The SPI API is asymmetric and the controller is freed as part of deregistration (unless it has been allocated using devm_spi_alloc_host/target()). A recent change converting the managed registration function to use devm_add_action_or_reset() inadvertently introduced a (mostly theoretical) regression where a non-devres managed controller could be freed as part of failed registration. This in turn would lead to use-after-free in controller driver error paths. Fix this by taking another reference before calling devm_add_action_or_reset() and not releasing it on errors for non-devres allocated controllers. An alternative would be a partial revert of the offending commit, but it is better to handle this explicitly until the API has been fixed (e.g. see 5e844cc37a5c ("spi: Introduce device-managed SPI controller allocation")). Fixes: b6376dbed8e1 ("spi: Simplify devm_spi_*_controller()") Reported-by: Felix Gu Link: https://lore.kernel.org/all/20260324145548.139952-1-ustc.gu@gmail.com/ Cc: Andy Shevchenko Signed-off-by: Johan Hovold Acked-by: Andy Shevchenko Link: https://patch.msgid.link/20260325145319.1132072-1-johan@kernel.org Signed-off-by: Mark Brown --- drivers/spi/spi.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 4101c2803eb3..9b1125556d29 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3534,8 +3534,19 @@ int devm_spi_register_controller(struct device *dev, if (ret) return ret; - return devm_add_action_or_reset(dev, devm_spi_unregister_controller, ctlr); + /* + * Prevent controller from being freed by spi_unregister_controller() + * if devm_add_action_or_reset() fails for a non-devres allocated + * controller. + */ + spi_controller_get(ctlr); + ret = devm_add_action_or_reset(dev, devm_spi_unregister_controller, ctlr); + + if (ret == 0 || ctlr->devm_allocated) + spi_controller_put(ctlr); + + return ret; } EXPORT_SYMBOL_GPL(devm_spi_register_controller); From b341c1176f2e001b3adf0b47154fc31589f7410e Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Thu, 19 Mar 2026 19:38:12 +0100 Subject: [PATCH 6/6] spi: spi-fsl-lpspi: fix teardown order issue (UAF) There is a teardown order issue in the driver. The SPI controller is registered using devm_spi_register_controller(), which delays unregistration of the SPI controller until after the fsl_lpspi_remove() function returns. As the fsl_lpspi_remove() function synchronously tears down the DMA channels, a running SPI transfer triggers the following NULL pointer dereference due to use after free: | fsl_lpspi 42550000.spi: I/O Error in DMA RX | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [...] | Call trace: | fsl_lpspi_dma_transfer+0x260/0x340 [spi_fsl_lpspi] | fsl_lpspi_transfer_one+0x198/0x448 [spi_fsl_lpspi] | spi_transfer_one_message+0x49c/0x7c8 | __spi_pump_transfer_message+0x120/0x420 | __spi_sync+0x2c4/0x520 | spi_sync+0x34/0x60 | spidev_message+0x20c/0x378 [spidev] | spidev_ioctl+0x398/0x750 [spidev] [...] Switch from devm_spi_register_controller() to spi_register_controller() in fsl_lpspi_probe() and add the corresponding spi_unregister_controller() in fsl_lpspi_remove(). Fixes: 5314987de5e5 ("spi: imx: add lpspi bus driver") Signed-off-by: Marc Kleine-Budde Link: https://patch.msgid.link/20260319-spi-fsl-lpspi-fixes-v1-1-b433e435b2d8@pengutronix.de Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-lpspi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index b361c1bb3e43..45390e9b8cae 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -1009,7 +1009,7 @@ static int fsl_lpspi_probe(struct platform_device *pdev) enable_irq(irq); } - ret = devm_spi_register_controller(&pdev->dev, controller); + ret = spi_register_controller(controller); if (ret < 0) { dev_err_probe(&pdev->dev, ret, "spi_register_controller error\n"); goto free_dma; @@ -1035,6 +1035,7 @@ static void fsl_lpspi_remove(struct platform_device *pdev) struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); + spi_unregister_controller(controller); fsl_lpspi_dma_exit(controller); pm_runtime_dont_use_autosuspend(fsl_lpspi->dev);