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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 31611C43603 for ; Tue, 17 Dec 2019 01:01:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1038C206D3 for ; Tue, 17 Dec 2019 01:01:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728328AbfLQBBn (ORCPT ); Mon, 16 Dec 2019 20:01:43 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34464 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726181AbfLQAva (ORCPT ); Mon, 16 Dec 2019 19:51:30 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ih15E-0003IT-5M; Tue, 17 Dec 2019 00:51:28 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ih15D-0005Rd-9p; Tue, 17 Dec 2019 00:51:27 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Eric Dumazet" , "syzbot" , "David S. Miller" Date: Tue, 17 Dec 2019 00:45:39 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 005/136] sch_cbq: validate TCA_CBQ_WRROPT to avoid crash In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit e9789c7cc182484fc031fd88097eb14cb26c4596 upstream. syzbot reported a crash in cbq_normalize_quanta() caused by an out of range cl->priority. iproute2 enforces this check, but malicious users do not. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI Modules linked in: CPU: 1 PID: 26447 Comm: syz-executor.1 Not tainted 5.3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:cbq_normalize_quanta.part.0+0x1fd/0x430 net/sched/sch_cbq.c:902 RSP: 0018:ffff8801a5c333b0 EFLAGS: 00010206 RAX: 0000000020000003 RBX: 00000000fffffff8 RCX: ffffc9000712f000 RDX: 00000000000043bf RSI: ffffffff83be8962 RDI: 0000000100000018 RBP: ffff8801a5c33420 R08: 000000000000003a R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000002ef R13: ffff88018da95188 R14: dffffc0000000000 R15: 0000000000000015 FS: 00007f37d26b1700(0000) GS:ffff8801dad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004c7cec CR3: 00000001bcd0a006 CR4: 00000000001626f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: [] cbq_normalize_quanta include/net/pkt_sched.h:27 [inline] [] cbq_addprio net/sched/sch_cbq.c:1097 [inline] [] cbq_set_wrr+0x2d7/0x450 net/sched/sch_cbq.c:1115 [] cbq_change_class+0x987/0x225b net/sched/sch_cbq.c:1537 [] tc_ctl_tclass+0x555/0xcd0 net/sched/sch_api.c:2329 [] rtnetlink_rcv_msg+0x485/0xc10 net/core/rtnetlink.c:5248 [] netlink_rcv_skb+0x17a/0x460 net/netlink/af_netlink.c:2510 [] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5266 [] netlink_unicast_kernel net/netlink/af_netlink.c:1324 [inline] [] netlink_unicast+0x536/0x720 net/netlink/af_netlink.c:1350 [] netlink_sendmsg+0x89a/0xd50 net/netlink/af_netlink.c:1939 [] sock_sendmsg_nosec net/socket.c:673 [inline] [] sock_sendmsg+0x12e/0x170 net/socket.c:684 [] ___sys_sendmsg+0x81d/0x960 net/socket.c:2359 [] __sys_sendmsg+0x105/0x1d0 net/socket.c:2397 [] SYSC_sendmsg net/socket.c:2406 [inline] [] SyS_sendmsg+0x29/0x30 net/socket.c:2404 [] do_syscall_64+0x528/0x770 arch/x86/entry/common.c:305 [] entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller [bwh: Backported to 3.16: - netlink doesn't support error messages - Keep calling nla_parse_nested() - Adjust context] Signed-off-by: Ben Hutchings --- net/sched/sch_cbq.c | 43 +++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) --- a/net/sched/sch_cbq.c +++ b/net/sched/sch_cbq.c @@ -1357,6 +1357,27 @@ static const struct nla_policy cbq_polic [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) }, }; +static int cbq_opt_parse(struct nlattr *tb[TCA_CBQ_MAX + 1], + struct nlattr *opt) +{ + int err; + + if (!opt) + return -EINVAL; + + err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy); + if (err < 0) + return err; + + if (tb[TCA_CBQ_WRROPT]) { + const struct tc_cbq_wrropt *wrr = nla_data(tb[TCA_CBQ_WRROPT]); + + if (wrr->priority > TC_CBQ_MAXPRIO) + err = -EINVAL; + } + return err; +} + static int cbq_init(struct Qdisc *sch, struct nlattr *opt) { struct cbq_sched_data *q = qdisc_priv(sch); @@ -1368,10 +1389,7 @@ static int cbq_init(struct Qdisc *sch, s hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); q->delay_timer.function = cbq_undelay; - if (!opt) - return -EINVAL; - - err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy); + err = cbq_opt_parse(tb, opt); if (err < 0) return err; @@ -1751,10 +1769,7 @@ cbq_change_class(struct Qdisc *sch, u32 struct cbq_class *parent; struct qdisc_rate_table *rtab = NULL; - if (opt == NULL) - return -EINVAL; - - err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy); + err = cbq_opt_parse(tb, opt); if (err < 0) return err;