[PATCH] w1: w1-gpio: Fix double-free of platform_data

[Alexey Ignatov]

struct w1_gpio_platform_data was allocated using devres when using
device tree. Then it was assigned to dev.platform_data, which leaded
to double free on device removal by devres and by direct
kfree(platform_data) in platform_device_release)

Signed-off-by: Alexey Ignatov <lexsz...@gmail.com>
---
 drivers/w1/masters/w1-gpio.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index dc5f6a2008bb..14e1a54f9f1f 100644
--- a/drivers/w1/masters/w1-gpio.c
+++ b/drivers/w1/masters/w1-gpio.c
@@ -95,15 +95,15 @@ static const struct of_device_id w1_gpio_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
 #endif
 
-static int w1_gpio_probe_dt(struct platform_device *pdev)
+static struct w1_gpio_platform_data *w1_gpio_probe_dt(struct platform_device 
*pdev)
 {
-       struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+       struct w1_gpio_platform_data *pdata;
        struct device_node *np = pdev->dev.of_node;
        int gpio;
 
        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
-               return -ENOMEM;
+               return ERR_PTR(-ENOMEM);
 
        if (of_get_property(np, "linux,open-drain", NULL))
                pdata->is_open_drain = 1;
@@ -115,25 +115,23 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
                                        "Failed to parse gpio property for data 
pin (%d)\n",
                                        gpio);
 
-               return gpio;
+               return ERR_PTR(gpio);
        }
        pdata->pin = gpio;
 
        gpio = of_get_gpio(np, 1);
        if (gpio == -EPROBE_DEFER)
-               return gpio;
+               return ERR_PTR(gpio);
        /* ignore other errors as the pullup gpio is optional */
        pdata->ext_pullup_enable_pin = gpio;
 
        gpio = of_get_named_gpio(np, "pu-gpios", 0);
        if (gpio == -EPROBE_DEFER)
-               return gpio;
+               return ERR_PTR(gpio);
        /* ignore other errors as the strong pullup gpio is optional */
        pdata->strong_pullup_enable_pin = gpio;
 
-       pdev->dev.platform_data = pdata;
-
-       return 0;
+       return pdata;
 }
 
 static int w1_gpio_probe(struct platform_device *pdev)
@@ -143,12 +141,12 @@ static int w1_gpio_probe(struct platform_device *pdev)
        int err;
 
        if (of_have_populated_dt()) {
-               err = w1_gpio_probe_dt(pdev);
-               if (err < 0)
-                       return err;
+               pdata = w1_gpio_probe_dt(pdev);
+               if (IS_ERR(pdata) < 0)
+                       return PTR_ERR(pdata);
        }
-
-       pdata = dev_get_platdata(&pdev->dev);
+       else
+               pdata = dev_get_platdata(&pdev->dev);
 
        if (!pdata) {
                dev_err(&pdev->dev, "No configuration data\n");
@@ -229,8 +227,9 @@ static int w1_gpio_probe(struct platform_device *pdev)
 static int w1_gpio_remove(struct platform_device *pdev)
 {
        struct w1_bus_master *master = platform_get_drvdata(pdev);
-       struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+       struct w1_gpio_platform_data *pdata = master->data;
 
+       pr_debug("%s: pdev=%p, master=%p\n", __func__, pdev, master);
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(0);
 
@@ -244,7 +243,8 @@ static int w1_gpio_remove(struct platform_device *pdev)
 
 static int __maybe_unused w1_gpio_suspend(struct device *dev)
 {
-       struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
+       struct w1_bus_master *master = dev_get_drvdata(dev);
+       struct w1_gpio_platform_data *pdata = master->data;
 
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(0);
@@ -254,7 +254,8 @@ static int __maybe_unused w1_gpio_suspend(struct device 
*dev)
 
 static int __maybe_unused w1_gpio_resume(struct device *dev)
 {
-       struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
+       struct w1_bus_master *master = dev_get_drvdata(dev);
+       struct w1_gpio_platform_data *pdata = master->data;
 
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(1);
-- 
2.11.0