From patchwork Thu Feb 28 03:16:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yue Haibing X-Patchwork-Id: 1049249 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 448ySR3dgGz9s4Z for ; Thu, 28 Feb 2019 14:18:47 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730524AbfB1DSa (ORCPT ); Wed, 27 Feb 2019 22:18:30 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:4181 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730131AbfB1DS3 (ORCPT ); Wed, 27 Feb 2019 22:18:29 -0500 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 3048ED77087345A0078C; Thu, 28 Feb 2019 11:18:27 +0800 (CST) Received: from localhost (10.177.31.96) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.408.0; Thu, 28 Feb 2019 11:18:21 +0800 From: Yue Haibing To: , , CC: , , YueHaibing Subject: [PATCH] xfrm: policy: Fix possible user after free in __xfrm_policy_unlink Date: Thu, 28 Feb 2019 11:16:23 +0800 Message-ID: <20190228031623.22184-1-yuehaibing@huawei.com> X-Mailer: git-send-email 2.10.2.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.177.31.96] X-CFilter-Loop: Reflected Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: YueHaibing UBSAN report this: UBSAN: Undefined behaviour in net/xfrm/xfrm_policy.c:1289:24 index 6 is out of range for type 'unsigned int [6]' CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.162-514.55.6.9.x86_64+ #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 0000000000000000 1466cf39b41b23c9 ffff8801f6b07a58 ffffffff81cb35f4 0000000041b58ab3 ffffffff83230f9c ffffffff81cb34e0 ffff8801f6b07a80 ffff8801f6b07a20 1466cf39b41b23c9 ffffffff851706e0 ffff8801f6b07ae8 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x114/0x1a0 lib/dump_stack.c:51 [] ubsan_epilogue+0x12/0x8f lib/ubsan.c:164 [] __ubsan_handle_out_of_bounds+0x16e/0x1b2 lib/ubsan.c:382 [] __xfrm_policy_unlink+0x3dd/0x5b0 net/xfrm/xfrm_policy.c:1289 [] xfrm_policy_delete+0x52/0xb0 net/xfrm/xfrm_policy.c:1309 [] xfrm_policy_timer+0x30b/0x590 net/xfrm/xfrm_policy.c:243 [] call_timer_fn+0x237/0x990 kernel/time/timer.c:1144 [] __run_timers kernel/time/timer.c:1218 [inline] [] run_timer_softirq+0x6ce/0xb80 kernel/time/timer.c:1401 [] __do_softirq+0x299/0xe10 kernel/softirq.c:273 [] invoke_softirq kernel/softirq.c:350 [inline] [] irq_exit+0x216/0x2c0 kernel/softirq.c:391 [] exiting_irq arch/x86/include/asm/apic.h:652 [inline] [] smp_apic_timer_interrupt+0x8b/0xc0 arch/x86/kernel/apic/apic.c:926 [] apic_timer_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:735 [] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:52 [] arch_safe_halt arch/x86/include/asm/paravirt.h:111 [inline] [] default_idle+0x27/0x430 arch/x86/kernel/process.c:446 [] arch_cpu_idle+0x15/0x20 arch/x86/kernel/process.c:437 [] default_idle_call+0x53/0x90 kernel/sched/idle.c:92 [] cpuidle_idle_call kernel/sched/idle.c:156 [inline] [] cpu_idle_loop kernel/sched/idle.c:251 [inline] [] cpu_startup_entry+0x60d/0x9a0 kernel/sched/idle.c:299 [] start_secondary+0x3c9/0x560 arch/x86/kernel/smpboot.c:245 The issue is triggered as this: xfrm_add_policy -->verify_newpolicy_info //check the index provided by user with XFRM_POLICY_MAX //In my case, the index is 0x6E6BB6, so it pass the check. -->xfrm_policy_construct //copy the user's policy and set xfrm_policy_timer -->xfrm_policy_insert --> __xfrm_policy_link //use the orgin dir, in my case is 2 --> xfrm_gen_index //generate policy index, there is 0x6E6BB6 then xfrm_policy_timer be fired xfrm_policy_timer --> xfrm_policy_id2dir //get dir from (policy index & 7), in my case is 6 --> xfrm_policy_delete --> __xfrm_policy_unlink //access policy_count[dir], trigger out of range access Reported-by: Hulk Robot Fixes: e682adf021be ("xfrm: Try to honor policy index if it's supplied by user") Signed-off-by: YueHaibing --- net/xfrm/xfrm_policy.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 8d1a898..b27eb742 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -316,6 +316,8 @@ static void xfrm_policy_timer(struct timer_list *t) goto out; dir = xfrm_policy_id2dir(xp->index); + if (dir >= XFRM_POLICY_MAX * 2) + dir = dir & XFRM_POLICY_MAX; if (xp->lft.hard_add_expires_seconds) { time64_t tmo = xp->lft.hard_add_expires_seconds +