From ec851b23084b3a0af8bf0f5e51d33a8d678bdc49 Mon Sep 17 00:00:00 2001 From: Zeng Heng Date: Fri, 25 Nov 2022 22:07:57 +0100 Subject: [PATCH 1/3] gpiolib: fix memory leak in gpiochip_setup_dev() Here is a backtrace report about memory leak detected in gpiochip_setup_dev(): unreferenced object 0xffff88810b406400 (size 512): comm "python3", pid 1682, jiffies 4295346908 (age 24.090s) backtrace: kmalloc_trace device_add device_private_init at drivers/base/core.c:3361 (inlined by) device_add at drivers/base/core.c:3411 cdev_device_add gpiolib_cdev_register gpiochip_setup_dev gpiochip_add_data_with_key gcdev_register() & gcdev_unregister() would call device_add() & device_del() (no matter CONFIG_GPIO_CDEV is enabled or not) to register/unregister device. However, if device_add() succeeds, some resource (like struct device_private allocated by device_private_init()) is not released by device_del(). Therefore, after device_add() succeeds by gcdev_register(), it needs to call put_device() to release resource in the error handle path. Here we move forward the register of release function, and let it release every piece of resource by put_device() instead of kfree(). While at it, fix another subtle issue, i.e. when gc->ngpio is equal to 0, we still call kcalloc() and, in case of further error, kfree() on the ZERO_PTR pointer, which is not NULL. It's not a bug per se, but rather waste of the resources and potentially wrong expectation about contents of the gdev->descs variable. Fixes: 159f3cd92f17 ("gpiolib: Defer gpio device setup until after gpiolib initialization") Signed-off-by: Zeng Heng Co-developed-by: Andy Shevchenko Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 42 ++++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 16 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4756ea08894f6..a70522aef3557 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -526,12 +526,13 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) if (ret) return ret; + /* From this point, the .release() function cleans up gpio_device */ + gdev->dev.release = gpiodevice_release; + ret = gpiochip_sysfs_register(gdev); if (ret) goto err_remove_device; - /* From this point, the .release() function cleans up gpio_device */ - gdev->dev.release = gpiodevice_release; dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base, gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic"); @@ -597,10 +598,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct fwnode_handle *fwnode = NULL; struct gpio_device *gdev; unsigned long flags; - int base = gc->base; unsigned int i; + u32 ngpios = 0; + int base = 0; int ret = 0; - u32 ngpios; if (gc->fwnode) fwnode = gc->fwnode; @@ -647,17 +648,12 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, else gdev->owner = THIS_MODULE; - gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL); - if (!gdev->descs) { - ret = -ENOMEM; - goto err_free_dev_name; - } - /* * Try the device properties if the driver didn't supply the number * of GPIO lines. */ - if (gc->ngpio == 0) { + ngpios = gc->ngpio; + if (ngpios == 0) { ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios); if (ret == -ENODATA) /* @@ -668,7 +664,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, */ ngpios = 0; else if (ret) - goto err_free_descs; + goto err_free_dev_name; gc->ngpio = ngpios; } @@ -676,13 +672,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, if (gc->ngpio == 0) { chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); ret = -EINVAL; - goto err_free_descs; + goto err_free_dev_name; } if (gc->ngpio > FASTPATH_NGPIO) chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n", gc->ngpio, FASTPATH_NGPIO); + gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL); + if (!gdev->descs) { + ret = -ENOMEM; + goto err_free_dev_name; + } + gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL); if (!gdev->label) { ret = -ENOMEM; @@ -701,11 +703,13 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, * it may be a pipe dream. It will not happen before we get rid * of the sysfs interface anyways. */ + base = gc->base; if (base < 0) { base = gpiochip_find_base(gc->ngpio); if (base < 0) { - ret = base; spin_unlock_irqrestore(&gpio_lock, flags); + ret = base; + base = 0; goto err_free_label; } /* @@ -816,6 +820,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, err_free_gpiochip_mask: gpiochip_remove_pin_ranges(gc); gpiochip_free_valid_mask(gc); + if (gdev->dev.release) { + /* release() has been registered by gpiochip_setup_dev() */ + put_device(&gdev->dev); + goto err_print_message; + } err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); @@ -829,13 +838,14 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, err_free_ida: ida_free(&gpio_ida, gdev->id); err_free_gdev: + kfree(gdev); +err_print_message: /* failures here can mean systems won't boot... */ if (ret != -EPROBE_DEFER) { pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__, - gdev->base, gdev->base + gdev->ngpio - 1, + base, base + (int)ngpios - 1, gc->label ? : "generic", ret); } - kfree(gdev); return ret; } EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key); From 45fecdb9f658d9c82960c98240bc0770ade19aca Mon Sep 17 00:00:00 2001 From: Xiongfeng Wang Date: Tue, 22 Nov 2022 20:35:08 +0800 Subject: [PATCH 2/3] gpio: amd8111: Fix PCI device reference count leak for_each_pci_dev() is implemented by pci_get_device(). The comment of pci_get_device() says that it will increase the reference count for the returned pci_dev and also decrease the reference count for the input pci_dev @from if it is not NULL. If we break for_each_pci_dev() loop with pdev not NULL, we need to call pci_dev_put() to decrease the reference count. Add the missing pci_dev_put() after the 'out' label. Since pci_dev_put() can handle NULL input parameter, there is no problem for the 'Device not found' branch. For the normal path, add pci_dev_put() in amd_gpio_exit(). Fixes: f942a7de047d ("gpio: add a driver for GPIO pins found on AMD-8111 south bridge chips") Signed-off-by: Xiongfeng Wang Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-amd8111.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpio/gpio-amd8111.c b/drivers/gpio/gpio-amd8111.c index 14e6b3e64add5..6f3ded619c8b2 100644 --- a/drivers/gpio/gpio-amd8111.c +++ b/drivers/gpio/gpio-amd8111.c @@ -226,7 +226,10 @@ static int __init amd_gpio_init(void) ioport_unmap(gp.pm); goto out; } + return 0; + out: + pci_dev_put(pdev); return err; } @@ -234,6 +237,7 @@ static void __exit amd_gpio_exit(void) { gpiochip_remove(&gp.chip); ioport_unmap(gp.pm); + pci_dev_put(gp.pdev); } module_init(amd_gpio_init); From 63ff545af73f759d1bd04198af8ed8577fb739fc Mon Sep 17 00:00:00 2001 From: Wang Yufen Date: Mon, 5 Dec 2022 14:19:56 +0800 Subject: [PATCH 3/3] gpio/rockchip: fix refcount leak in rockchip_gpiolib_register() The node returned by of_get_parent() with refcount incremented, of_node_put() needs be called when finish using it. So add it in the end of of_pinctrl_get(). Fixes: 936ee2675eee ("gpio/rockchip: add driver for rockchip gpio") Signed-off-by: Wang Yufen Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-rockchip.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c index 870910bb9dd35..200e43a6f4b4f 100644 --- a/drivers/gpio/gpio-rockchip.c +++ b/drivers/gpio/gpio-rockchip.c @@ -610,6 +610,7 @@ static int rockchip_gpiolib_register(struct rockchip_pin_bank *bank) return -ENODATA; pctldev = of_pinctrl_get(pctlnp); + of_node_put(pctlnp); if (!pctldev) return -ENODEV;