From nobody Thu Dec 18 09:44:01 2025 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 59A7BC001B0 for ; Mon, 14 Aug 2023 01:34:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231458AbjHNBeJ (ORCPT ); Sun, 13 Aug 2023 21:34:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230441AbjHNBeC (ORCPT ); Sun, 13 Aug 2023 21:34:02 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 172FFE52; Sun, 13 Aug 2023 18:34:00 -0700 (PDT) Received: from kwepemi500026.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4RPH2b55j0z1GDXK; Mon, 14 Aug 2023 09:32:39 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) by kwepemi500026.china.huawei.com (7.221.188.247) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Mon, 14 Aug 2023 09:33:55 +0800 From: Dong Chenchen To: , , CC: , , , , , , , , , Dong Chenchen Subject: [PATCH net] net: xfrm: skip policies marked as dead while reinserting policies Date: Mon, 14 Aug 2023 09:33:52 +0800 Message-ID: <20230814013352.2771452-1-dongchenchen2@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemi500026.china.huawei.com (7.221.188.247) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" BUG: KASAN: slab-use-after-free in xfrm_policy_inexact_list_reinsert+0xb6/0= x430 Read of size 1 at addr ffff8881051f3bf8 by task ip/668 CPU: 2 PID: 668 Comm: ip Not tainted 6.5.0-rc5-00182-g25aa0bebba72-dirty #64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13 04/01/= 2014 Call Trace: dump_stack_lvl+0x72/0xa0 print_report+0xd0/0x620 kasan_report+0xb6/0xf0 xfrm_policy_inexact_list_reinsert+0xb6/0x430 xfrm_policy_inexact_insert_node.constprop.0+0x537/0x800 xfrm_policy_inexact_alloc_chain+0x23f/0x320 xfrm_policy_inexact_insert+0x6b/0x590 xfrm_policy_insert+0x3b1/0x480 xfrm_add_policy+0x23c/0x3c0 xfrm_user_rcv_msg+0x2d0/0x510 netlink_rcv_skb+0x10d/0x2d0 xfrm_netlink_rcv+0x49/0x60 netlink_unicast+0x3fe/0x540 netlink_sendmsg+0x528/0x970 sock_sendmsg+0x14a/0x160 ____sys_sendmsg+0x4fc/0x580 ___sys_sendmsg+0xef/0x160 __sys_sendmsg+0xf7/0x1b0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x73/0xdd The root cause is: cpu 0 cpu1 xfrm_dump_policy xfrm_policy_walk list_move_tail xfrm_add_policy ... ... xfrm_policy_inexact_list_reinsert list_for_each_entry_reverse if (!policy->bydst_reinsert) //read non-existent policy xfrm_dump_policy_done xfrm_policy_walk_done list_del(&walk->walk.all); If dump_one_policy() returns err (triggered by netlink socket), xfrm_policy_walk() will move walk initialized by socket to list net->xfrm.policy_all. so this socket becomes visible in the global policy list. The head *walk can be traversed when users add policies with different prefixlen and trigger xfrm_policy node merge. It can be fixed by skip such "policies" with walk.dead set to 1. Fixes: 9cf545ebd591 ("xfrm: policy: store inexact policies in a tree ordere= d by destination address") Fixes: 12a169e7d8f4 ("ipsec: Put dumpers on the dump list") Signed-off-by: Dong Chenchen Reviewed-by: Leon Romanovsky --- net/xfrm/xfrm_policy.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index d6b405782b63..5b56faad78e0 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -848,6 +848,9 @@ static void xfrm_policy_inexact_list_reinsert(struct ne= t *net, matched_d =3D 0; =20 list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) { + if (policy->walk.dead) + continue; + struct hlist_node *newpos =3D NULL; bool matches_s, matches_d; =20 --=20 2.25.1