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| author | Wang Hai <wanghai38@huawei.com> | 2021-01-28 19:32:50 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-30 13:27:16 +0100 |
| commit | 4c3134adf3391ffc8ac959be83ea8b6c56342cc3 (patch) | |
| tree | ef15a06b70048bc2213aa8ad0e023abe3ad40973 /mm/slub.c | |
| parent | 24c1a3d010531ebaa08f8da46f3506829d29ae9a (diff) | |
| download | linux-rt-4c3134adf3391ffc8ac959be83ea8b6c56342cc3.tar.gz | |
Revert "mm/slub: fix a memory leak in sysfs_slab_add()"
commit 757fed1d0898b893d7daa84183947c70f27632f3 upstream.
This reverts commit dde3c6b72a16c2db826f54b2d49bdea26c3534a2.
syzbot report a double-free bug. The following case can cause this bug.
- mm/slab_common.c: create_cache(): if the __kmem_cache_create() fails,
it does:
out_free_cache:
kmem_cache_free(kmem_cache, s);
- but __kmem_cache_create() - at least for slub() - will have done
sysfs_slab_add(s)
-> sysfs_create_group() .. fails ..
-> kobject_del(&s->kobj); .. which frees s ...
We can't remove the kmem_cache_free() in create_cache(), because other
error cases of __kmem_cache_create() do not free this.
So, revert the commit dde3c6b72a16 ("mm/slub: fix a memory leak in
sysfs_slab_add()") to fix this.
Reported-by: syzbot+d0bd96b4696c1ef67991@syzkaller.appspotmail.com
Fixes: dde3c6b72a16 ("mm/slub: fix a memory leak in sysfs_slab_add()")
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/mm/slub.c b/mm/slub.c index 7ccfc043c28e..5c48a8a0524a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5648,10 +5648,8 @@ static int sysfs_slab_add(struct kmem_cache *s) s->kobj.kset = cache_kset(s); err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name); - if (err) { - kobject_put(&s->kobj); + if (err) goto out; - } err = sysfs_create_group(&s->kobj, &slab_attr_group); if (err) |