Re: [-mm3 PATCH] (Retry) Check the return value of kobject_add andetc.

From: Cornelia Huck
Date: Thu Apr 05 2007 - 05:09:44 EST


On Thu, 5 Apr 2007 12:54:11 +0800,
WANG Cong <xiyou.wangcong@xxxxxxxxx> wrote:

> --- linux-2.6.21-rc5-mm3/fs/partitions/check.c.orig 2007-03-30 21:35:45.000000000 +0800
> +++ linux-2.6.21-rc5-mm3/fs/partitions/check.c 2007-04-02 21:29:02.000000000 +0800
> @@ -385,10 +385,18 @@ void add_partition(struct gendisk *disk,
> p->kobj.parent = &disk->kobj;
> p->kobj.ktype = &ktype_part;
> kobject_init(&p->kobj);
> - kobject_add(&p->kobj);
> + if (kobject_add(&p->kobj)) {
> + kfree(p);
> + return;
> + }
> if (!disk->part_uevent_suppress)
> kobject_uevent(&p->kobj, KOBJ_ADD);
> - sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem");
> + if (sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem")) {
> + kobject_uevent(&p->kobj, KOBJ_REMOVE);
> + kobject_del(&p->kobj);
> + kfree(p);

You should use kobject_put instead of kfree, since someone could have
(theoretically) obtained a reference on the object after the
kobject_add. (Or just use kobject_unregister, if the delete uevent
isn't suppressed anyway.)

> + return;
> + }
> if (flags & ADDPART_FLAG_WHOLEDISK) {
> static struct attribute addpartattr = {
> .name = "whole_disk",
> @@ -396,7 +404,13 @@ void add_partition(struct gendisk *disk,
> .owner = THIS_MODULE,
> };
>
> - sysfs_create_file(&p->kobj, &addpartattr);
> + if (sysfs_create_file(&p->kobj, &addpartattr)) {
> + sysfs_remove_link(&p->kobj, "subsystem");
> + kobject_uevent(&p->kobj, KOBJ_REMOVE);
> + kobject_del(&p->kobj);
> + kfree(p);

Same here.

> + return;
> + }
> }
> partition_sysfs_add_subdir(p);
> disk->part[part-1] = p;
>
>
>

-
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