From 8f3cbcd6b440032ebc7f7d48a1689dcc70a4eb98 Mon Sep 17 00:00:00 2001 From: ChiYuan Huang Date: Tue, 6 Dec 2022 15:22:21 +0800 Subject: regulator: core: Use different devices for resource allocation and DT lookup Following by the below discussion, there's the potential UAF issue between regulator and mfd. https://lore.kernel.org/all/20221128143601.1698148-1-yangyingliang@huawei.com/ From the analysis of Yingliang CPU A |CPU B mt6370_probe() | devm_mfd_add_devices() | |mt6370_regulator_probe() | regulator_register() | //allocate init_data and add it to devres | regulator_of_get_init_data() i2c_unregister_device() | device_del() | devres_release_all() | // init_data is freed | release_nodes() | | // using init_data causes UAF | regulator_register() It's common to use mfd core to create child device for the regulator. In order to do the DT lookup for init data, the child that registered the regulator would pass its parent as the parameter. And this causes init data resource allocated to its parent, not itself. The issue happen when parent device is going to release and regulator core is still doing some operation of init data constraint for the regulator of child device. To fix it, this patch expand 'regulator_register' API to use the different devices for init data allocation and DT lookup. Reported-by: Yang Yingliang Signed-off-by: ChiYuan Huang Link: https://lore.kernel.org/r/1670311341-32664-1-git-send-email-u0084500@gmail.com Signed-off-by: Mark Brown --- drivers/regulator/of_regulator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/regulator/of_regulator.c') diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index f7529f1bf8b2..1b65e5e4e40f 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -505,7 +505,7 @@ struct regulator_init_data *regulator_of_get_init_data(struct device *dev, struct device_node *child; struct regulator_init_data *init_data = NULL; - child = regulator_of_get_init_node(dev, desc); + child = regulator_of_get_init_node(config->dev, desc); if (!child) return NULL; -- cgit v1.2.3