From patchwork Thu Oct 20 02:42:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: shaozhengchao X-Patchwork-Id: 13012555 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D05B5C433FE for ; Thu, 20 Oct 2022 02:35:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229569AbiJTCfK (ORCPT ); Wed, 19 Oct 2022 22:35:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230470AbiJTCfI (ORCPT ); Wed, 19 Oct 2022 22:35:08 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44F2998364 for ; Wed, 19 Oct 2022 19:34:58 -0700 (PDT) Received: from dggpeml500026.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MtBS91ngjzpVYZ; Thu, 20 Oct 2022 10:31:37 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpeml500026.china.huawei.com (7.185.36.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 10:34:21 +0800 From: Zhengchao Shao To: , , , , CC: , , , , , , , , Subject: [PATCH net] net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed Date: Thu, 20 Oct 2022 10:42:13 +0800 Message-ID: <20221020024213.264324-1-shaozhengchao@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml500026.china.huawei.com (7.185.36.106) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org When the ops_init() interface is invoked to initialize the net, but ops->init() fails, data is released. However, the ptr pointer in net->gen is invalid. In this case, when nfqnl_nf_hook_drop() is invoked to release the net, invalid address access occurs. The process is as follows: setup_net() ops_init() data = kzalloc(...) ---> alloc "data" net_assign_generic() ---> assign "date" to ptr in net->gen ... ops->init() ---> failed ... kfree(data); ---> ptr in net->gen is invalid ... ops_exit_list() ... nfqnl_nf_hook_drop() *q = nfnl_queue_pernet(net) ---> q is invalid The following is the Call Trace information: BUG: KASAN: use-after-free in nfqnl_nf_hook_drop+0x264/0x280 Read of size 8 at addr ffff88810396b240 by task ip/15855 Call Trace: dump_stack_lvl+0x8e/0xd1 print_report+0x155/0x454 kasan_report+0xba/0x1f0 nfqnl_nf_hook_drop+0x264/0x280 nf_queue_nf_hook_drop+0x8b/0x1b0 __nf_unregister_net_hook+0x1ae/0x5a0 nf_unregister_net_hooks+0xde/0x130 ops_exit_list+0xb0/0x170 setup_net+0x7ac/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Allocated by task 15855: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0xa1/0xb0 __kmalloc+0x49/0xb0 ops_init+0xe7/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 15855: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x155/0x1b0 slab_free_freelist_hook+0x11b/0x220 __kmem_cache_free+0xa4/0x360 ops_init+0xb9/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: f875bae06533 ("net: Automatically allocate per namespace data.") Signed-off-by: Zhengchao Shao --- net/core/net_namespace.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 0ec2f5906a27..f64654df71a2 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -117,6 +117,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data) static int ops_init(const struct pernet_operations *ops, struct net *net) { + struct net_generic *ng; int err = -ENOMEM; void *data = NULL; @@ -135,7 +136,13 @@ static int ops_init(const struct pernet_operations *ops, struct net *net) if (!err) return 0; + if (ops->id && ops->size) { cleanup: + ng = rcu_dereference_protected(net->gen, + lockdep_is_held(&pernet_ops_rwsem)); + ng->ptr[*ops->id] = NULL; + } + kfree(data); out: