[PATCH v3 2/9] powerpc/secvar: Add missing kobject release callback to secvar_ktype

[Ian Rogers <irogers@xxxxxxxxxx>]

In add_var(), a struct kobject is dynamically allocated with
kzalloc_obj() and initialized with secvar_ktype. If kobject_add() or
sysfs_create_file() fails, kobject_put(kobj) is called to clean up.
However, secvar_ktype does not define a .release callback, which results
in a memory leak of kobj (and a pr_debug warning in kobject_cleanup()
when CONFIG_DEBUG_KOBJECT_RELEASE is enabled).

Provide a secvar_release() callback that calls kfree(kobj).

Fixes: bd5d9c743d38 ("powerpc: expose secure variables to userspace via sysfs")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 arch/powerpc/kernel/secvar-sysfs.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/kernel/secvar-sysfs.c 
b/arch/powerpc/kernel/secvar-sysfs.c
index 395399bbab2c..f3f6ac25ea78 100644
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -126,7 +126,13 @@ static const struct attribute_group secvar_attr_group = {
 };
 __ATTRIBUTE_GROUPS(secvar_attr);
 
+static void secvar_release(struct kobject *kobj)
+{
+       kfree(kobj);
+}
+
 static const struct kobj_type secvar_ktype = {
+       .release        = secvar_release,
        .sysfs_ops      = &kobj_sysfs_ops,
        .default_groups = secvar_attr_groups,
 };
-- 
2.56.0.455.g6c5a503b38-goog