Re: [PATCH 10/14] scsi: osd: fix device_register() error handling

James Bottomley
2010-09-20T15:55:06Z

On Mon, 2010-09-20 at 17:42 +0200, Boaz Harrosh wrote:
> I think I have a compromise. If it is indeed the dev_set_name() leak
> then we can just deallocate the name on the error return path. Therefore
> any drivers that have the device embedded and rely on it been freed without
> calling _put will be fine as before. And these calling _put will be fine
> as well.
>
> See below
> Boaz
> ---
> git diff --stat -p -M drivers/base/core.c
> drivers/base/core.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index d1b2c9a..054fac2 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1068,6 +1068,7 @@ done:
> if (parent)
> put_device(parent);
> name_error:
> + kfree(dev->kobj.name);
> kfree(dev->p);
> dev->p = NULL;
> goto done;

That's not really good enough ... it will result in a double free
because the final put (if there is one) will free the name again.

This would work, but it feels a bit wrong to be poking at the kobject
from within the driver core ... perhaps a kobject_free_name() call might
be better?

James

---

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d1b2c9a..88ffaca 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1067,6 +1067,8 @@ done:
cleanup_device_parent(dev);
if (parent)
put_device(parent);
+ kfree(dev->kobj.name);
+ dev->kobj.name = NULL;
name_error:
kfree(dev->p);
dev->p = NULL;