From patchwork Mon Oct 31 06:08:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hawkins Jiawei X-Patchwork-Id: 13025409 X-Patchwork-Delegate: kuba@kernel.org 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 C4272FA3740 for ; Mon, 31 Oct 2022 06:08:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229610AbiJaGIm (ORCPT ); Mon, 31 Oct 2022 02:08:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229487AbiJaGIk (ORCPT ); Mon, 31 Oct 2022 02:08:40 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B301310CE; Sun, 30 Oct 2022 23:08:39 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id e129so9840243pgc.9; Sun, 30 Oct 2022 23:08:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=iEE08gyNxXm/V2oNqjJuD7X/v5POQZGV6saTMMYOy0I=; b=pe7Z/HoFYVd22iReZXMg/yQhJGXQCbDTDTjxqJoDfsGnPXU2r6xPW1xBStxvz+u9Uj NlGCW++oC0//NtdCNnfGpcYAoz38+o27CfDgLkpZ6Ucqf3GrZwamjIETWPsdjQMQYBow W2BWEMUAsAdjkIWNorvzojKqgxMpwgGdkUhPp+izVwoF9/PBhYVYrozupT8TO/GjYQxS Ac49G9tiMena5j3mB0m2HRExHdN2prqCK1K80opvSfkcnkWpG8RREY0fiGVy4RC37IO5 NGaLOBNRGnzceorVhG1+tA08H9Wuby7xcyGjeAiAFrPiGTvMo9YF0a5y7XgSPWf9oEWS 4wPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=iEE08gyNxXm/V2oNqjJuD7X/v5POQZGV6saTMMYOy0I=; b=gjXaZCNGpiAEuZkQOgqO5TdLS+fdZRRZL47mpmY2sDXU5huq196cF2yusgx4QsXMza y9cjwlcAGddazgDtxLxeCzFnB8BTWzYpV/duRvxa5WILquBvCJT3mjDGmZD0um6zRxVW P7+IBeGfSGTREZGtD1crTDdIUxI5groR1r8KT+M+GZnti//MyiuHrSrMfPZ8b0WvCVog bVbXs5dB0hKqLhY8u5wi+VWlRJs1OsfTbS9EDY7aWaTC+jtH1+qnePXu/nNH6YkdQsHj CVc1CkVo2pzL+ED/K9/+Fx0Lwt1HDAnx6+hb9S0Eu7xHOu3tRuyMeRwRDY2bjBdZJ56r 3H9Q== X-Gm-Message-State: ACrzQf0eKLD1eoMkmywngb9kfA0RcFcF4+tSJdeB2bbJDhnl0uV9V1VU +YzHjtfPhUPXC3pfEy2Kfvw= X-Google-Smtp-Source: AMsMyM4eag2Tjic63uXgSpJBkNHOPb3Ibcy9CUWLoFzAaSQoDSjqm7KWDcD9v2ojOjmkQo8HrICcaA== X-Received: by 2002:a63:5455:0:b0:46f:be60:af9b with SMTP id e21-20020a635455000000b0046fbe60af9bmr3441248pgm.307.1667196519118; Sun, 30 Oct 2022 23:08:39 -0700 (PDT) Received: from localhost ([159.226.94.113]) by smtp.gmail.com with ESMTPSA id n6-20020a170902d2c600b00181f8523f60sm3583174plc.225.2022.10.30.23.08.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 Oct 2022 23:08:38 -0700 (PDT) From: Hawkins Jiawei To: yin31149@gmail.com, Jamal Hadi Salim , Cong Wang , Jiri Pirko , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: syzbot+232ebdbd36706c965ebf@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com, 18801353760@163.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] net: sched: fix memory leak in tcindex_set_parms Date: Mon, 31 Oct 2022 14:08:35 +0800 Message-Id: <20221031060835.11722-1-yin31149@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Syzkaller reports a memory leak as follows: ==================================== BUG: memory leak unreferenced object 0xffff88810c287f00 (size 256): comm "syz-executor105", pid 3600, jiffies 4294943292 (age 12.990s) hex dump (first 32 bytes): 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 00 00 00 00 00 ................ backtrace: [] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046 [] kmalloc include/linux/slab.h:576 [inline] [] kmalloc_array include/linux/slab.h:627 [inline] [] kcalloc include/linux/slab.h:659 [inline] [] tcf_exts_init include/net/pkt_cls.h:250 [inline] [] tcindex_set_parms+0xa7/0xbe0 net/sched/cls_tcindex.c:342 [] tcindex_change+0xdf/0x120 net/sched/cls_tcindex.c:553 [] tc_new_tfilter+0x4f2/0x1100 net/sched/cls_api.c:2147 [] rtnetlink_rcv_msg+0x4dc/0x5d0 net/core/rtnetlink.c:6082 [] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2540 [] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] [] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345 [] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921 [] sock_sendmsg_nosec net/socket.c:714 [inline] [] sock_sendmsg+0x56/0x80 net/socket.c:734 [] ____sys_sendmsg+0x178/0x410 net/socket.c:2482 [] ___sys_sendmsg+0xa8/0x110 net/socket.c:2536 [] __sys_sendmmsg+0x105/0x330 net/socket.c:2622 [] __do_sys_sendmmsg net/socket.c:2651 [inline] [] __se_sys_sendmmsg net/socket.c:2648 [inline] [] __x64_sys_sendmmsg+0x24/0x30 net/socket.c:2648 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd ==================================== Kernel will uses tcindex_change() to change an existing traffic-control-indices filter properties. During the process of changing, kernel will clears the old traffic-control-indices filter result, and updates it by RCU assigning new traffic-control-indices data. Yet the problem is that, kernel will clears the old traffic-control-indices filter result, without destroying its tcf_exts structure, which triggers the above memory leak. This patch solves it by using tcf_exts_destroy() to destroy the tcf_exts structure in old traffic-control-indices filter result. Link: https://lore.kernel.org/all/0000000000001de5c505ebc9ec59@google.com/ Reported-by: syzbot+232ebdbd36706c965ebf@syzkaller.appspotmail.com Tested-by: syzbot+232ebdbd36706c965ebf@syzkaller.appspotmail.com Signed-off-by: Hawkins Jiawei --- net/sched/cls_tcindex.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c index 1c9eeb98d826..dc872a794337 100644 --- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -338,6 +338,9 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, struct tcf_result cr = {}; int err, balloc = 0; struct tcf_exts e; +#ifdef CONFIG_NET_CLS_ACT + struct tcf_exts old_e = {}; +#endif err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE); if (err < 0) @@ -479,6 +482,14 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, } if (old_r && old_r != r) { +#ifdef CONFIG_NET_CLS_ACT + /* r->exts is not copied from old_r->exts, and + * the following code will clears the old_r, so + * we need to destroy it after updating the tp->root, + * to avoid memory leak bug. + */ + old_e = old_r->exts; +#endif err = tcindex_filter_result_init(old_r, cp, net); if (err < 0) { kfree(f); @@ -510,6 +521,9 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, tcf_exts_destroy(&new_filter_result.exts); } +#ifdef CONFIG_NET_CLS_ACT + tcf_exts_destroy(&old_e); +#endif if (oldp) tcf_queue_work(&oldp->rwork, tcindex_partial_destroy_work); return 0;