From 2252607d327d5219a6331b50e6ec266d56402be0 Mon Sep 17 00:00:00 2001 From: Gregory Fong Date: Wed, 17 Jun 2015 18:00:40 -0700 Subject: gpio: brcmstb: fix null ptr dereference in driver remove If a failure occurs during probe, brcmstb_gpio_remove() is called. In remove, we call platform_get_drvdata(), but at the time of failure in the probe the driver data hadn't yet been set which leads to a NULL ptr dereference in the remove's list_for_each. Call platform_set_drvdata() and set up list head right after allocating the priv struct to both avoid the null pointer dereference that could occur today. To guard against potential future changes, check for null pointer in remove. Reported-by: Tim Ross Signed-off-by: Gregory Fong Signed-off-by: Linus Walleij --- drivers/gpio/gpio-brcmstb.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'drivers/gpio/gpio-brcmstb.c') diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c index 7a3cb1fa0a76..4630a8133ea6 100644 --- a/drivers/gpio/gpio-brcmstb.c +++ b/drivers/gpio/gpio-brcmstb.c @@ -87,6 +87,15 @@ static int brcmstb_gpio_remove(struct platform_device *pdev) struct brcmstb_gpio_bank *bank; int ret = 0; + if (!priv) { + dev_err(&pdev->dev, "called %s without drvdata!\n", __func__); + return -EFAULT; + } + + /* + * You can lose return values below, but we report all errors, and it's + * more important to actually perform all of the steps. + */ list_for_each(pos, &priv->bank_list) { bank = list_entry(pos, struct brcmstb_gpio_bank, node); ret = bgpio_remove(&bank->bgc); @@ -143,6 +152,8 @@ static int brcmstb_gpio_probe(struct platform_device *pdev) priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; + platform_set_drvdata(pdev, priv); + INIT_LIST_HEAD(&priv->bank_list); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); reg_base = devm_ioremap_resource(dev, res); @@ -153,7 +164,6 @@ static int brcmstb_gpio_probe(struct platform_device *pdev) priv->reg_base = reg_base; priv->pdev = pdev; - INIT_LIST_HEAD(&priv->bank_list); if (brcmstb_gpio_sanity_check_banks(dev, np, res)) return -EINVAL; @@ -221,8 +231,6 @@ static int brcmstb_gpio_probe(struct platform_device *pdev) dev_info(dev, "Registered %d banks (GPIO(s): %d-%d)\n", priv->num_banks, priv->gpio_base, gpio_base - 1); - platform_set_drvdata(pdev, priv); - return 0; fail: -- cgit