[PATCH] mm: Fix kobject memleak in SLUB

[PATCH] mm: Fix kobject memleak in SLUB

[Tobin C. Harding]

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 <tobin@kernel.org>
---
 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

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

[Pekka Enberg]

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 <tobin@kernel.org>

Reviewed-by: Pekka Enberg <penberg@kernel.org>

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

[Greg Kroah-Hartman]

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 <tobin@kernel.org>

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

[Tobin C. Harding]

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 <tobin@kernel.org>
> ---
>  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.