From patchwork Mon Sep 13 18:08:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 12490499 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 X-Spam-Level: X-Spam-Status: No, score=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, USER_AGENT_GIT autolearn=ham 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 99061C433EF for ; Mon, 13 Sep 2021 18:08:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 867AF60EE9 for ; Mon, 13 Sep 2021 18:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346540AbhIMSJ5 (ORCPT ); Mon, 13 Sep 2021 14:09:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346508AbhIMSJ4 (ORCPT ); Mon, 13 Sep 2021 14:09:56 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BB4DC061574 for ; Mon, 13 Sep 2021 11:08:40 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id 5so6377037plo.5 for ; Mon, 13 Sep 2021 11:08:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=rc7hIuppL6cvx8tvXc+DIAlI+K6MbZyPBOAeXSifZP8=; b=o4NYcDASsZWPGU5r01O+7Z5wcPDAa6V+KCv23zC424xAMUle4+WmF9aBhoepMgX5aW otgn+1tE55j/NeTyreIwy0DXVfcGinJHnqpZAsdNBZ4IUyExPz18Xvssw6OJ2OCaOa43 boNRdMzuE9am+aDlOF4XgO4z+C6AvpoD3X/eUJ5q4F1bSlNDnQ8bumuY6qNoAbkhgTwY CdYRj3Epe7pSbMAIrMVIq7FQCETMhPr8ySDt3kU7y8IqAT92aCeJDPXwILqGYHHc+Fi7 QYtmRErtlapIissGkKo8qdjbbNR8Doc762TpcYuEA6UygNnMmrM9GOKTCYhwk/0KH9Bm 4E3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=rc7hIuppL6cvx8tvXc+DIAlI+K6MbZyPBOAeXSifZP8=; b=qsxQY7PeovAPvue7L3/dvvBOTVnoFjMx7MNsQqKYRZBox8xbyRKdpMNJ5W3NVlA26h zLV1Vsuxbp+/AzdPH2jfggYegEp9HH6zxw0ulFhysjz7CxuScLQFffjy8Fs3ngybLjfQ 2vroJ7PA9fTPHPk0l/PCvro/ImZnvGNYXymOUT51ZZUWKG5zJ4sM2gDVboMxWSlh1qSl W61K3Cx4fVZ/jzxDsPX8TdM+IoJcohJ2/h1Y9nvn/eneGYudDm/p2fuXl3uF0f33ecqH Og2gIk1kN3FuznoHgekpQ3UsAogKL7Bp8/pynaLKeHZhXdRV2D6uS0/mKbVbhZtYEBj4 EFWg== X-Gm-Message-State: AOAM5325z73t5vA4Bp8ZWQ3T64Ih+VYUqG7IEzhtbrQuKU9/Bkr15w3P rSEeoaRUwAO++RUI86EkcVM= X-Google-Smtp-Source: ABdhPJzN3hKRrSPk4GZolyvUDMYTe6hjTb3bT9MxrosuHyvdGQFM2hmzdpGsyWgITa+1TmtL7W73zw== X-Received: by 2002:a17:90a:cf0d:: with SMTP id h13mr787501pju.61.1631556519918; Mon, 13 Sep 2021 11:08:39 -0700 (PDT) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:77da:7605:5a70:a0cd]) by smtp.gmail.com with ESMTPSA id l22sm9395955pgo.45.2021.09.13.11.08.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Sep 2021 11:08:39 -0700 (PDT) From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski Cc: netdev , Eric Dumazet , Eric Dumazet Subject: [PATCH net] net-caif: avoid user-triggerable WARN_ON(1) Date: Mon, 13 Sep 2021 11:08:36 -0700 Message-Id: <20210913180836.3943779-1-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.33.0.309.g3052b89438-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Eric Dumazet syszbot triggers this warning, which looks something we can easily prevent. If we initialize priv->list_field in chnl_net_init(), then always use list_del_init(), we can remove robust_list_del() completely. WARNING: CPU: 0 PID: 3233 at net/caif/chnl_net.c:67 robust_list_del net/caif/chnl_net.c:67 [inline] WARNING: CPU: 0 PID: 3233 at net/caif/chnl_net.c:67 chnl_net_uninit+0xc9/0x2e0 net/caif/chnl_net.c:375 Modules linked in: CPU: 0 PID: 3233 Comm: syz-executor.3 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:robust_list_del net/caif/chnl_net.c:67 [inline] RIP: 0010:chnl_net_uninit+0xc9/0x2e0 net/caif/chnl_net.c:375 Code: 89 eb e8 3a a3 ba f8 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 bf 01 00 00 48 81 fb 00 14 4e 8d 48 8b 2b 75 d0 e8 17 a3 ba f8 <0f> 0b 5b 5d 41 5c 41 5d e9 0a a3 ba f8 4c 89 e3 e8 02 a3 ba f8 4c RSP: 0018:ffffc90009067248 EFLAGS: 00010202 RAX: 0000000000008780 RBX: ffffffff8d4e1400 RCX: ffffc9000fd34000 RDX: 0000000000040000 RSI: ffffffff88bb6e49 RDI: 0000000000000003 RBP: ffff88802cd9ee08 R08: 0000000000000000 R09: ffffffff8d0e6647 R10: ffffffff88bb6dc2 R11: 0000000000000000 R12: ffff88803791ae08 R13: dffffc0000000000 R14: 00000000e600ffce R15: ffff888073ed3480 FS: 00007fed10fa0700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c322000 CR3: 00000000164a6000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: register_netdevice+0xadf/0x1500 net/core/dev.c:10347 ipcaif_newlink+0x4c/0x260 net/caif/chnl_net.c:468 __rtnl_newlink+0x106d/0x1750 net/core/rtnetlink.c:3458 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3506 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 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+0x44/0xae Fixes: cc36a070b590 ("net-caif: add CAIF netdevice") Signed-off-by: Eric Dumazet --- net/caif/chnl_net.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c index 37b67194c0dfe412d51b92d9b5f8513e5b2db34a..414dc5671c45edb447342b934683b0eaf1695b39 100644 --- a/net/caif/chnl_net.c +++ b/net/caif/chnl_net.c @@ -53,20 +53,6 @@ struct chnl_net { enum caif_states state; }; -static void robust_list_del(struct list_head *delete_node) -{ - struct list_head *list_node; - struct list_head *n; - ASSERT_RTNL(); - list_for_each_safe(list_node, n, &chnl_net_list) { - if (list_node == delete_node) { - list_del(list_node); - return; - } - } - WARN_ON(1); -} - static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt) { struct sk_buff *skb; @@ -364,6 +350,7 @@ static int chnl_net_init(struct net_device *dev) ASSERT_RTNL(); priv = netdev_priv(dev); strncpy(priv->name, dev->name, sizeof(priv->name)); + INIT_LIST_HEAD(&priv->list_field); return 0; } @@ -372,7 +359,7 @@ static void chnl_net_uninit(struct net_device *dev) struct chnl_net *priv; ASSERT_RTNL(); priv = netdev_priv(dev); - robust_list_del(&priv->list_field); + list_del_init(&priv->list_field); } static const struct net_device_ops netdev_ops = { @@ -537,7 +524,7 @@ static void __exit chnl_exit_module(void) rtnl_lock(); list_for_each_safe(list_node, _tmp, &chnl_net_list) { dev = list_entry(list_node, struct chnl_net, list_field); - list_del(list_node); + list_del_init(list_node); delete_device(dev); } rtnl_unlock();