From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B67C0C468BD for ; Sat, 8 Jun 2019 11:46:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90183214DA for ; Sat, 8 Jun 2019 11:46:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559994414; bh=Z7uhBh0Wb9NnA8EX92lFbl7JWfZGdTbu64NvuQKqewE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mOT/Q2B/ixn42WU9i6U7pC+6isGdFpzSjZJfIokdmuHoXD+XwSnOnOt4hNgitAxPP OoEsi81nJpgdqO4cTbBPIn5WM8NRJzjJ7aG2Duk1eAUkB/rbhOGFHh9a5x8hDaK0Ek mNbw4Q+zRJQk4ZV674wav+JEgBvTDLjcoPl278HM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728822AbfFHLqy (ORCPT ); Sat, 8 Jun 2019 07:46:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:35580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728728AbfFHLqx (ORCPT ); Sat, 8 Jun 2019 07:46:53 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 79786216FD; Sat, 8 Jun 2019 11:46:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559994412; bh=Z7uhBh0Wb9NnA8EX92lFbl7JWfZGdTbu64NvuQKqewE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gvHgKqAKvugwQGzs0tbUYsD+QX/Qs3pTZ0o++rbxjAoEPzxjVz6amucClnxUIS99v FJD7IBh+dyjbtp74vxlOSGYxbcmbMlKU7mVvOO9RwRr0d0tXRKNaXLNZ3s82zAyz0N 2GtgD266QOW+HzeUU/v4KzWnkT+UlABaa009g/rQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: YueHaibing , Hulk Robot , Julian Anastasov , Simon Horman , Pablo Neira Ayuso , Sasha Levin , netdev@vger.kernel.org, lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org Subject: [PATCH AUTOSEL 4.14 04/31] ipvs: Fix use-after-free in ip_vs_in Date: Sat, 8 Jun 2019 07:46:15 -0400 Message-Id: <20190608114646.9415-4-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190608114646.9415-1-sashal@kernel.org> References: <20190608114646.9415-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: YueHaibing [ Upstream commit 719c7d563c17b150877cee03a4b812a424989dfa ] BUG: KASAN: use-after-free in ip_vs_in.part.29+0xe8/0xd20 [ip_vs] Read of size 4 at addr ffff8881e9b26e2c by task sshd/5603 CPU: 0 PID: 5603 Comm: sshd Not tainted 4.19.39+ #30 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: dump_stack+0x71/0xab print_address_description+0x6a/0x270 kasan_report+0x179/0x2c0 ip_vs_in.part.29+0xe8/0xd20 [ip_vs] ip_vs_in+0xd8/0x170 [ip_vs] nf_hook_slow+0x5f/0xe0 __ip_local_out+0x1d5/0x250 ip_local_out+0x19/0x60 __tcp_transmit_skb+0xba1/0x14f0 tcp_write_xmit+0x41f/0x1ed0 ? _copy_from_iter_full+0xca/0x340 __tcp_push_pending_frames+0x52/0x140 tcp_sendmsg_locked+0x787/0x1600 ? tcp_sendpage+0x60/0x60 ? inet_sk_set_state+0xb0/0xb0 tcp_sendmsg+0x27/0x40 sock_sendmsg+0x6d/0x80 sock_write_iter+0x121/0x1c0 ? sock_sendmsg+0x80/0x80 __vfs_write+0x23e/0x370 vfs_write+0xe7/0x230 ksys_write+0xa1/0x120 ? __ia32_sys_read+0x50/0x50 ? __audit_syscall_exit+0x3ce/0x450 do_syscall_64+0x73/0x200 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7ff6f6147c60 Code: 73 01 c3 48 8b 0d 28 12 2d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 5d 73 2d 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 RSP: 002b:00007ffd772ead18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000034 RCX: 00007ff6f6147c60 RDX: 0000000000000034 RSI: 000055df30a31270 RDI: 0000000000000003 RBP: 000055df30a31270 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffd772ead70 R11: 0000000000000246 R12: 00007ffd772ead74 R13: 00007ffd772eae20 R14: 00007ffd772eae24 R15: 000055df2f12ddc0 Allocated by task 6052: kasan_kmalloc+0xa0/0xd0 __kmalloc+0x10a/0x220 ops_init+0x97/0x190 register_pernet_operations+0x1ac/0x360 register_pernet_subsys+0x24/0x40 0xffffffffc0ea016d do_one_initcall+0x8b/0x253 do_init_module+0xe3/0x335 load_module+0x2fc0/0x3890 __do_sys_finit_module+0x192/0x1c0 do_syscall_64+0x73/0x200 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6067: __kasan_slab_free+0x130/0x180 kfree+0x90/0x1a0 ops_free_list.part.7+0xa6/0xc0 unregister_pernet_operations+0x18b/0x1f0 unregister_pernet_subsys+0x1d/0x30 ip_vs_cleanup+0x1d/0xd2f [ip_vs] __x64_sys_delete_module+0x20c/0x300 do_syscall_64+0x73/0x200 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8881e9b26600 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 2092 bytes inside of 4096-byte region [ffff8881e9b26600, ffff8881e9b27600) The buggy address belongs to the page: page:ffffea0007a6c800 count:1 mapcount:0 mapping:ffff888107c0e600 index:0x0 compound_mapcount: 0 flags: 0x17ffffc0008100(slab|head) raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff888107c0e600 raw: 0000000000000000 0000000080070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected while unregistering ipvs module, ops_free_list calls __ip_vs_cleanup, then nf_unregister_net_hooks be called to do remove nf hook entries. It need a RCU period to finish, however net->ipvs is set to NULL immediately, which will trigger NULL pointer dereference when a packet is hooked and handled by ip_vs_in where net->ipvs is dereferenced. Another scene is ops_free_list call ops_free to free the net_generic directly while __ip_vs_cleanup finished, then calling ip_vs_in will triggers use-after-free. This patch moves nf_unregister_net_hooks from __ip_vs_cleanup() to __ip_vs_dev_cleanup(), where rcu_barrier() is called by unregister_pernet_device -> unregister_pernet_operations, that will do the needed grace period. Reported-by: Hulk Robot Fixes: efe41606184e ("ipvs: convert to use pernet nf_hook api") Suggested-by: Julian Anastasov Signed-off-by: YueHaibing Acked-by: Julian Anastasov Signed-off-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/ipvs/ip_vs_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index d1c0378144f3..ee97ce176b9a 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -2268,7 +2268,6 @@ static void __net_exit __ip_vs_cleanup(struct net *net) { struct netns_ipvs *ipvs = net_ipvs(net); - nf_unregister_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); ip_vs_service_net_cleanup(ipvs); /* ip_vs_flush() with locks */ ip_vs_conn_net_cleanup(ipvs); ip_vs_app_net_cleanup(ipvs); @@ -2283,6 +2282,7 @@ static void __net_exit __ip_vs_dev_cleanup(struct net *net) { struct netns_ipvs *ipvs = net_ipvs(net); EnterFunction(2); + nf_unregister_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); ipvs->enable = 0; /* Disable packet reception */ smp_wmb(); ip_vs_sync_net_cleanup(ipvs); -- 2.20.1