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>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c
index 73068e50e56d..3250fc1df0aa 100644
--- 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;
 }