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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 071AEC2D0DB for ; Thu, 30 Jan 2020 18:52:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0A2B20702 for ; Thu, 30 Jan 2020 18:52:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580410351; bh=Hs5PgR11akM00vuuaeTXEUHOa44riobDyTbwi8I4R5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OVc8hxJ5OLL5CYVtE2V6KDT9Z9DftnEKfXzYT7LlRwQiR7A1/oeIC0CJ7HWevPkD4 M/BfLt1wQgrvX5eSaUEkGnGtETsR/sGfUAH7APkqk8+YqSBEAdKMTU7KX7gs/P1lTk BO08JehyQatFe0sRUm+poO8fMF11MQBvOrhh39tQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730595AbgA3SnV (ORCPT ); Thu, 30 Jan 2020 13:43:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:51790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730563AbgA3SnP (ORCPT ); Thu, 30 Jan 2020 13:43:15 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC0DC20702; Thu, 30 Jan 2020 18:43:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580409794; bh=Hs5PgR11akM00vuuaeTXEUHOa44riobDyTbwi8I4R5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C9Kc7fzej3TuxOU+2QYZKAg/fXghEwYy6cRj5q3RoZgrXyuMpVxgye4AcA1J5qLR8 /hO+mVd4xjV1Pj2Ku5WkbdnGreOJc2NP2ioNG9XW1oF05bcziXy9y0AIegtaZgq0gI AbuZOhBjI0rWsSLY6qgfVP0BtUxaNcFJSTRXvGdE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot+03c4738ed29d5d366ddf@syzkaller.appspotmail.com, Cong Wang , "David S. Miller" Subject: [PATCH 5.4 035/110] net_sched: ematch: reject invalid TCF_EM_SIMPLE Date: Thu, 30 Jan 2020 19:38:11 +0100 Message-Id: <20200130183619.517719472@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200130183613.810054545@linuxfoundation.org> References: <20200130183613.810054545@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit 55cd9f67f1e45de8517cdaab985fb8e56c0bc1d8 ] It is possible for malicious userspace to set TCF_EM_SIMPLE bit even for matches that should not have this bit set. This can fool two places using tcf_em_is_simple() 1) tcf_em_tree_destroy() -> memory leak of em->data if ops->destroy() is NULL 2) tcf_em_tree_dump() wrongly report/leak 4 low-order bytes of a kernel pointer. BUG: memory leak unreferenced object 0xffff888121850a40 (size 32): comm "syz-executor927", pid 7193, jiffies 4294941655 (age 19.840s) hex dump (first 32 bytes): 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000f67036ea>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] [<00000000f67036ea>] slab_post_alloc_hook mm/slab.h:586 [inline] [<00000000f67036ea>] slab_alloc mm/slab.c:3320 [inline] [<00000000f67036ea>] __do_kmalloc mm/slab.c:3654 [inline] [<00000000f67036ea>] __kmalloc_track_caller+0x165/0x300 mm/slab.c:3671 [<00000000fab0cc8e>] kmemdup+0x27/0x60 mm/util.c:127 [<00000000d9992e0a>] kmemdup include/linux/string.h:453 [inline] [<00000000d9992e0a>] em_nbyte_change+0x5b/0x90 net/sched/em_nbyte.c:32 [<000000007e04f711>] tcf_em_validate net/sched/ematch.c:241 [inline] [<000000007e04f711>] tcf_em_tree_validate net/sched/ematch.c:359 [inline] [<000000007e04f711>] tcf_em_tree_validate+0x332/0x46f net/sched/ematch.c:300 [<000000007a769204>] basic_set_parms net/sched/cls_basic.c:157 [inline] [<000000007a769204>] basic_change+0x1d7/0x5f0 net/sched/cls_basic.c:219 [<00000000e57a5997>] tc_new_tfilter+0x566/0xf70 net/sched/cls_api.c:2104 [<0000000074b68559>] rtnetlink_rcv_msg+0x3b2/0x4b0 net/core/rtnetlink.c:5415 [<00000000b7fe53fb>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477 [<00000000e83a40d0>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5442 [<00000000d62ba933>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] [<00000000d62ba933>] netlink_unicast+0x223/0x310 net/netlink/af_netlink.c:1328 [<0000000088070f72>] netlink_sendmsg+0x2c0/0x570 net/netlink/af_netlink.c:1917 [<00000000f70b15ea>] sock_sendmsg_nosec net/socket.c:639 [inline] [<00000000f70b15ea>] sock_sendmsg+0x54/0x70 net/socket.c:659 [<00000000ef95a9be>] ____sys_sendmsg+0x2d0/0x300 net/socket.c:2330 [<00000000b650f1ab>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2384 [<0000000055bfa74a>] __sys_sendmsg+0x80/0xf0 net/socket.c:2417 [<000000002abac183>] __do_sys_sendmsg net/socket.c:2426 [inline] [<000000002abac183>] __se_sys_sendmsg net/socket.c:2424 [inline] [<000000002abac183>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2424 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot+03c4738ed29d5d366ddf@syzkaller.appspotmail.com Cc: Cong Wang Acked-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/ematch.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/sched/ematch.c +++ b/net/sched/ematch.c @@ -238,6 +238,9 @@ static int tcf_em_validate(struct tcf_pr goto errout; if (em->ops->change) { + err = -EINVAL; + if (em_hdr->flags & TCF_EM_SIMPLE) + goto errout; err = em->ops->change(net, data, data_len, em); if (err < 0) goto errout;