From 011568eb3117a1b0e1b2e980de37a4ec47952617 Mon Sep 17 00:00:00 2001 From: Xiaolei Wang Date: Wed, 28 Feb 2024 11:04:08 +0800 Subject: mm/slab: Fix a kmemleak in kmem_cache_destroy() For earlier kmem cache creation, slab_sysfs_init() has not been called. Consequently, kmem_cache_destroy() cannot utilize kobj_type::release to release the kmem_cache structure. Therefore, tweak kmem_cache_release() to use slab_kmem_cache_release() for releasing kmem_cache when slab_state isn't FULL. This will fixes the memory leaks like following: unreferenced object 0xffff0000c2d87080 (size 128): comm "swapper/0", pid 1, jiffies 4294893428 hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 6b 6b 6b 6b .....N......kkkk ff ff ff ff ff ff ff ff b8 ab 48 89 00 80 ff ff.....H..... backtrace (crc 8819d0f6): [] kmemleak_alloc+0xb0/0xc4 [] kmem_cache_alloc_node+0x288/0x3a8 [] __kmem_cache_create+0x1e4/0x64c [] kmem_cache_create_usercopy+0x1c4/0x2cc [] kmem_cache_create+0x1c/0x28 [] arm_v7s_alloc_pgtable+0x1c0/0x6d4 [] alloc_io_pgtable_ops+0xe8/0x2d0 [] arm_v7s_do_selftests+0xe0/0x73c [] do_one_initcall+0x11c/0x7ac [] kernel_init_freeable+0x53c/0xbb8 [] kernel_init+0x24/0x144 [] ret_from_fork+0x10/0x20 Signed-off-by: Xiaolei Wang Reviewed-by: Chengming Zhou Signed-off-by: Vlastimil Babka --- mm/slab_common.c | 8 ++++++-- mm/slub.c | 6 ++---- 2 files changed, 8 insertions(+), 6 deletions(-) (limited to 'mm') diff --git a/mm/slab_common.c b/mm/slab_common.c index e19544043fdf4..7d60cfc2b30f6 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -404,8 +404,12 @@ EXPORT_SYMBOL(kmem_cache_create); */ static void kmem_cache_release(struct kmem_cache *s) { - sysfs_slab_unlink(s); - sysfs_slab_release(s); + if (slab_state >= FULL) { + sysfs_slab_unlink(s); + sysfs_slab_release(s); + } else { + slab_kmem_cache_release(s); + } } #else static void kmem_cache_release(struct kmem_cache *s) diff --git a/mm/slub.c b/mm/slub.c index e28929e6e2526..0e02e072693b6 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -6794,14 +6794,12 @@ out_del_kobj: void sysfs_slab_unlink(struct kmem_cache *s) { - if (slab_state >= FULL) - kobject_del(&s->kobj); + kobject_del(&s->kobj); } void sysfs_slab_release(struct kmem_cache *s) { - if (slab_state >= FULL) - kobject_put(&s->kobj); + kobject_put(&s->kobj); } /* -- cgit 1.2.3-korg