]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
Revert "mm/slub: fix a memory leak in sysfs_slab_add()"
authorWang Hai <wanghai38@huawei.com>
Thu, 28 Jan 2021 11:32:50 +0000 (19:32 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 30 Jan 2021 12:55:16 +0000 (13:55 +0100)
commitbf5eb7d21ab01c12c35df05dddd15f9f2ad5ba71
tree2ad794ece97c5f73fd8aed24c59390ad3dd19788
parent43f2e6077f441d681f0337ab91f7c4c2d4c62761
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>
mm/slub.c