2019-04-27 23:43:27

by Tobin C. Harding

Subject: [PATCH] mm: Fix kobject memleak in SLUB

Currently error return from kobject_init_and_add() is not followed by a
call to kobject_put(). This means there is a memory leak.

Add call to kobject_put() in error path of kobject_init_and_add().

Signed-off-by: Tobin C. Harding <[email protected]>
---
mm/slub.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/slub.c b/mm/slub.c
index d30ede89f4a6..84a9d6c06c27 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5756,8 +5756,10 @@ static int sysfs_slab_add(struct kmem_cache *s)

s->kobj.kset = kset;
err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
- if (err)
+ if (err) {
+ kobject_put(&s->kobj);
goto out;
+ }

err = sysfs_create_group(&s->kobj, &slab_attr_group);
if (err)
--
2.21.0

2019-04-28 06:11:39

by Pekka Enberg

Subject: Re: [PATCH] mm: Fix kobject memleak in SLUB

On 28/04/2019 2.40, Tobin C. Harding wrote:
> Currently error return from kobject_init_and_add() is not followed by a
> call to kobject_put(). This means there is a memory leak.
>
> Add call to kobject_put() in error path of kobject_init_and_add().
>
> Signed-off-by: Tobin C. Harding <[email protected]>

Reviewed-by: Pekka Enberg <[email protected]>

2019-04-28 16:14:20

by Greg Kroah-Hartman

Subject: Re: [PATCH] mm: Fix kobject memleak in SLUB

On Sun, Apr 28, 2019 at 09:40:00AM +1000, Tobin C. Harding wrote:
> Currently error return from kobject_init_and_add() is not followed by a
> call to kobject_put(). This means there is a memory leak.
>
> Add call to kobject_put() in error path of kobject_init_and_add().
>
> Signed-off-by: Tobin C. Harding <[email protected]>

Reviewed-by: Greg Kroah-Hartman <[email protected]>

2019-04-30 22:56:12

by Tobin C. Harding

Subject: Re: [PATCH] mm: Fix kobject memleak in SLUB

On Sun, Apr 28, 2019 at 09:40:00AM +1000, Tobin C. Harding wrote:
> Currently error return from kobject_init_and_add() is not followed by a
> call to kobject_put(). This means there is a memory leak.
>
> Add call to kobject_put() in error path of kobject_init_and_add().
>
> Signed-off-by: Tobin C. Harding <[email protected]>
> ---
> mm/slub.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index d30ede89f4a6..84a9d6c06c27 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -5756,8 +5756,10 @@ static int sysfs_slab_add(struct kmem_cache *s)
>
> s->kobj.kset = kset;
> err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
> - if (err)
> + if (err) {
> + kobject_put(&s->kobj);
> goto out;
> + }
>
> err = sysfs_create_group(&s->kobj, &slab_attr_group);
> if (err)
> --
> 2.21.0
>

This patch is not _completely_ correct. Please do not consider for
merge. There are a bunch of these on various LKML lists, once the
confusion has cleared I'll re-spin v2.

thanks,
Tobin.