[PATCH 0/4] Refactor __kmem_cache_create() and fix memory leak

From: Liu Shixin
Date: Mon Oct 24 2022 - 02:54:17 EST


I found a memory leak of kobj->name in sysfs_slab_add() which is introduced
by 80da026a8e5d ("mm/slub: fix slab double-free in case of duplicate sysfs filename").
Following the rules stated in the comment for kobject_init_and_add():

If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object.

We should use kobject_put() to free kobject.

But we can't simply add kobject_put() since it will free kmem_cache too.
If we use kobject_put(), we need to skip other release functions.

In this series, We refactor the code to separate sysfs_slab_add() and
debugfs_slab_add() from __kmem_cache_create(), and then use kobject_put()
to free kobject in sysfs_slab_add(). This can fix the memory leak of
kobject->name.

Liu Shixin (4):
mm/slab_common: Move cache_name to create_cache()
mm/slub: rename kmem_cache_release to slab_release in slub.c
mm/slab_common: Separate sysfs_slab_add() and debugfs_slab_add() from
__kmem_cache_create()
mm/slab_common: Fix memory leak of kobj->name in sysfs_slab_add()

include/linux/slub_def.h | 11 ++++++++
mm/slab_common.c | 42 ++++++++++++++++--------------
mm/slub.c | 56 +++++++++++-----------------------------
3 files changed, 48 insertions(+), 61 deletions(-)

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2.25.1