mfd: vexpress: fix error handling vexpress_syscfg_regmap_init()

This function should be returning an ERR_PTR() on failure instead of
NULL.  Also there is a use after free bug if regmap_init() fails because
we free "func" and then dereference doing the return.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c
index 73068e5..3250fc1 100644 (file)
--- a/drivers/misc/vexpress-syscfg.c
+++ b/drivers/misc/vexpress-syscfg.c
@@ -199,7 +199,7 @@ static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
        func = kzalloc(sizeof(*func) + sizeof(*func->template) * num,
                        GFP_KERNEL);
        if (!func)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        func->syscfg = syscfg;
        func->num_templates = num;
@@ -231,10 +231,14 @@ static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
        func->regmap = regmap_init(dev, NULL, func,
                        &vexpress_syscfg_regmap_config);
 
-       if (IS_ERR(func->regmap))
+       if (IS_ERR(func->regmap)) {
+               void *err = func->regmap;
+
                kfree(func);
-       else
-               list_add(&func->list, &syscfg->funcs);
+               return err;
+       }
+
+       list_add(&func->list, &syscfg->funcs);
 
        return func->regmap;
 }