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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 6FACCC4361A for ; Mon, 12 Apr 2021 09:31:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48B5861209 for ; Mon, 12 Apr 2021 09:31:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242172AbhDLJ17 (ORCPT ); Mon, 12 Apr 2021 05:27:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:54864 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238337AbhDLJED (ORCPT ); Mon, 12 Apr 2021 05:04:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CE0956128E; Mon, 12 Apr 2021 09:01:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618218090; bh=PdRofA4xbs04jCkKVLwbmMnho9haWm1MiYUZlij7kTE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FMnCP+vcou4ELtP2OrTEohMpEonIIbxUsp621mkOW2yJ6kRfz6kuyXNn0dJyhRSN8 6YXB49qt/XKF0HL0rMWdJYFislNGWK+0Go3pMFsWDN9YCiQhTFo5V+jim1JBXLvL5u kzMxcPK4kiGEWKLpzkdrCNNKo7yfaSzb8s+t2wgc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Tikhomirov , Eric Dumazet , "David S. Miller" Subject: [PATCH 5.11 068/210] net: sched: sch_teql: fix null-pointer dereference Date: Mon, 12 Apr 2021 10:39:33 +0200 Message-Id: <20210412084018.271275682@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210412084016.009884719@linuxfoundation.org> References: <20210412084016.009884719@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Tikhomirov commit 1ffbc7ea91606e4abd10eb60de5367f1c86daf5e upstream. Reproduce: modprobe sch_teql tc qdisc add dev teql0 root teql0 This leads to (for instance in Centos 7 VM) OOPS: [ 532.366633] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 [ 532.366733] IP: [] teql_destroy+0x18/0x100 [sch_teql] [ 532.366825] PGD 80000001376d5067 PUD 137e37067 PMD 0 [ 532.366906] Oops: 0000 [#1] SMP [ 532.366987] Modules linked in: sch_teql ... [ 532.367945] CPU: 1 PID: 3026 Comm: tc Kdump: loaded Tainted: G ------------ T 3.10.0-1062.7.1.el7.x86_64 #1 [ 532.368041] Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.2 04/01/2014 [ 532.368125] task: ffff8b7d37d31070 ti: ffff8b7c9fdbc000 task.ti: ffff8b7c9fdbc000 [ 532.368224] RIP: 0010:[] [] teql_destroy+0x18/0x100 [sch_teql] [ 532.368320] RSP: 0018:ffff8b7c9fdbf8e0 EFLAGS: 00010286 [ 532.368394] RAX: ffffffffc0612490 RBX: ffff8b7cb1565e00 RCX: ffff8b7d35ba2000 [ 532.368476] RDX: ffff8b7d35ba2000 RSI: 0000000000000000 RDI: ffff8b7cb1565e00 [ 532.368557] RBP: ffff8b7c9fdbf8f8 R08: ffff8b7d3fd1f140 R09: ffff8b7d3b001600 [ 532.368638] R10: ffff8b7d3b001600 R11: ffffffff84c7d65b R12: 00000000ffffffd8 [ 532.368719] R13: 0000000000008000 R14: ffff8b7d35ba2000 R15: ffff8b7c9fdbf9a8 [ 532.368800] FS: 00007f6a4e872740(0000) GS:ffff8b7d3fd00000(0000) knlGS:0000000000000000 [ 532.368885] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 532.368961] CR2: 00000000000000a8 CR3: 00000001396ee000 CR4: 00000000000206e0 [ 532.369046] Call Trace: [ 532.369159] [] qdisc_create+0x36e/0x450 [ 532.369268] [] ? ns_capable+0x29/0x50 [ 532.369366] [] ? nla_parse+0x32/0x120 [ 532.369442] [] tc_modify_qdisc+0x13c/0x610 [ 532.371508] [] rtnetlink_rcv_msg+0xa7/0x260 [ 532.372668] [] ? sock_has_perm+0x75/0x90 [ 532.373790] [] ? rtnl_newlink+0x890/0x890 [ 532.374914] [] netlink_rcv_skb+0xab/0xc0 [ 532.376055] [] rtnetlink_rcv+0x28/0x30 [ 532.377204] [] netlink_unicast+0x170/0x210 [ 532.378333] [] netlink_sendmsg+0x308/0x420 [ 532.379465] [] sock_sendmsg+0xb6/0xf0 [ 532.380710] [] ? __xfs_filemap_fault+0x8e/0x1d0 [xfs] [ 532.381868] [] ? xfs_filemap_fault+0x2c/0x30 [xfs] [ 532.383037] [] ? __do_fault.isra.61+0x8a/0x100 [ 532.384144] [] ___sys_sendmsg+0x3e9/0x400 [ 532.385268] [] ? handle_mm_fault+0x39d/0x9b0 [ 532.386387] [] ? __do_page_fault+0x238/0x500 [ 532.387472] [] __sys_sendmsg+0x51/0x90 [ 532.388560] [] SyS_sendmsg+0x12/0x20 [ 532.389636] [] system_call_fastpath+0x25/0x2a [ 532.390704] [] ? system_call_after_swapgs+0xae/0x146 [ 532.391753] Code: 00 00 00 00 00 00 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 41 55 41 54 53 48 8b b7 48 01 00 00 48 89 fb <48> 8b 8e a8 00 00 00 48 85 c9 74 43 48 89 ca eb 0f 0f 1f 80 00 [ 532.394036] RIP [] teql_destroy+0x18/0x100 [sch_teql] [ 532.395127] RSP [ 532.396179] CR2: 00000000000000a8 Null pointer dereference happens on master->slaves dereference in teql_destroy() as master is null-pointer. When qdisc_create() calls teql_qdisc_init() it imediately fails after check "if (m->dev == dev)" because both devices are teql0, and it does not set qdisc_priv(sch)->m leaving it zero on error path, then qdisc_create() imediately calls teql_destroy() which does not expect zero master pointer and we get OOPS. Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Signed-off-by: Pavel Tikhomirov Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_teql.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/sched/sch_teql.c +++ b/net/sched/sch_teql.c @@ -134,6 +134,9 @@ teql_destroy(struct Qdisc *sch) struct teql_sched_data *dat = qdisc_priv(sch); struct teql_master *master = dat->m; + if (!master) + return; + prev = master->slaves; if (prev) { do {