kobject: Add sanity check for kset->kobj.ktype in kset_register()

When I register a kset in the following way:
	static struct kset my_kset;
	kobject_set_name(&my_kset.kobj, "my_kset");
        ret = kset_register(&my_kset);

A null pointer dereference exception is occurred:
[ 4453.568337] Unable to handle kernel NULL pointer dereference at \
virtual address 0000000000000028
... ...
[ 4453.810361] Call trace:
[ 4453.813062]  kobject_get_ownership+0xc/0x34
[ 4453.817493]  kobject_add_internal+0x98/0x274
[ 4453.822005]  kset_register+0x5c/0xb4
[ 4453.825820]  my_kobj_init+0x44/0x1000 [my_kset]
... ...

Because I didn't initialize my_kset.kobj.ktype.

According to the description in Documentation/core-api/kobject.rst:
 - A ktype is the type of object that embeds a kobject.  Every structure
   that embeds a kobject needs a corresponding ktype.

So add sanity check to make sure kset->kobj.ktype is not NULL.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20230805084114.1298-2-thunder.leizhen@huaweicloud.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Zhen Lei 2023-08-05 16:41:13 +08:00 committed by Greg Kroah-Hartman
parent f7bb242601
commit 4d0fe8c52b

View File

@ -861,6 +861,11 @@ int kset_register(struct kset *k)
if (!k)
return -EINVAL;
if (!k->kobj.ktype) {
pr_err("must have a ktype to be initialized properly!\n");
return -EINVAL;
}
kset_init(k);
err = kobject_add_internal(&k->kobj);
if (err) {