kobject: fix dereference before null check on kobj

The kobj pointer is being null-checked so potentially it could be null,
however, the ktype declaration before the null check is dereferencing kobj
hence we have a potential null pointer deference. Fix this by moving the
assignment of ktype after kobj has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/lib/kobject.c b/lib/kobject.c
index a30ee04..095bcb5 100644 (file)
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -603,12 +603,13 @@ EXPORT_SYMBOL_GPL(kobject_move);
 void kobject_del(struct kobject *kobj)
 {
        struct kernfs_node *sd;
-       const struct kobj_type *ktype = get_ktype(kobj);
+       const struct kobj_type *ktype;
 
        if (!kobj)
                return;
 
        sd = kobj->sd;
+       ktype = get_ktype(kobj);
 
        if (ktype)
                sysfs_remove_groups(kobj, ktype->default_groups);