From patchwork Wed Jun 9 15:46:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Changbin Du X-Patchwork-Id: 12310585 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=-15.8 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,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 AA015C48BCF for ; Wed, 9 Jun 2021 15:46:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8564F61073 for ; Wed, 9 Jun 2021 15:46:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234611AbhFIPss (ORCPT ); Wed, 9 Jun 2021 11:48:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234044AbhFIPsr (ORCPT ); Wed, 9 Jun 2021 11:48:47 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9BADC061574; Wed, 9 Jun 2021 08:46:52 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id x10so12742929plg.3; Wed, 09 Jun 2021 08:46:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=e4aq/DyThBNoxMj07ot0bkg9LS2d0lWSCk/xRtR93s8=; b=YMWlm3oqjplYs/n4JR52ku/DKZ7xKAGjqx3rXE/XvL/DmvDQfJcZ3sKDrH8moXCoKe OvHl43kF5z1m/FPQm+1sZlzvoCD3N5EgAYZAvbtQSuqXW3azfHLHs9oCPWRlwIsnM6np BLcEPyV6E0tO1TVTFpo0pJV+a9DtRaXUR6KJ275tTJvhNROBmtWbJhcprbyRWHa12gkM vtU4L1AfQgDxF29A8rrjxZb+UwXERw6NVPGOZzvXa7HNrwGe49ryaAxxZkIu8m3XI9kv RnTYtwXDG0QHX/kmp3HCr9J8Dr47BOvYaN8qfTJ9L78dPGF85QpTEU/avVdNhuumFj2F UlEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=e4aq/DyThBNoxMj07ot0bkg9LS2d0lWSCk/xRtR93s8=; b=af4Xiu6TrrLv+/Pl2nQgCKajWWvLPEdpC79GTnK7vIV/zc1Qygr9WzV1a8HJyWQaXf /plIhtgwGb2vj6CFU/h96tE3nZAouY6ZXwhsHuagu5geHTebAnKW1ErqKxOlGy/iOsfv m2S970xmy2zu8ZNQQvVTO9+Mbr6ulmd9Rurw28ZzwdwUxT6K1ZFdMYKr8WHzDbN9QO1c xj4d2gdjEtl/4vjij1KtUAmu+ga9lrja65hLvxRs4Vwc4K6ZEI5dvoQmfOkFlqBU7b/w 0ZBhLsYxnvKHrCHczQY1IWJNSL/w0K68Bf9LNcPqvpTduDyLH7AtESvQcoTzgy5TP/C2 ShKw== X-Gm-Message-State: AOAM5317DTL0BgIfeZw+k69sfJqp0QUl4Hz4Wu6yCmV1cVp1yVSkHhi4 wQNKpDYGh96mx/QFajVf4tzDvhJDKsn/rQ== X-Google-Smtp-Source: ABdhPJz9it0NlbsWH0N+DNWPmelWAKAr0gcHsh1EmXiwp5vViDogczoL5DxxX5fEnkvRDT4wZI6uPA== X-Received: by 2002:a17:902:b94a:b029:10d:6f56:eeac with SMTP id h10-20020a170902b94ab029010d6f56eeacmr403539pls.54.1623253612379; Wed, 09 Jun 2021 08:46:52 -0700 (PDT) Received: from WRT-WX9.. ([141.164.41.4]) by smtp.gmail.com with ESMTPSA id u20sm39753pfn.192.2021.06.09.08.46.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Jun 2021 08:46:52 -0700 (PDT) From: Changbin Du To: Alexander Viro Cc: "David S. Miller" , Jakub Kici nski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Changbin Du , Cong Wang , David Laight , Christian Brauner Subject: [PATCH v2] net: do not invoke open_related_ns when NET_NS is disabled Date: Wed, 9 Jun 2021 23:46:35 +0800 Message-Id: <20210609154635.46792-1-changbin.du@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org When NET_NS is not enabled, socket ioctl cmd SIOCGSKNS should do nothing but acknowledge userspace it is not supported. Otherwise, kernel would panic wherever nsfs trys to access ns->ops since the proc_ns_operations is not implemented in this case. [7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010 [7.670268] pgd = 32b54000 [7.670544] [00000010] *pgd=00000000 [7.671861] Internal error: Oops: 5 [#1] SMP ARM [7.672315] Modules linked in: [7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16 [7.673309] Hardware name: Generic DT based system [7.673642] PC is at nsfs_evict+0x24/0x30 [7.674486] LR is at clear_inode+0x20/0x9c The same to tun SIOCGSKNS command. Signed-off-by: Changbin Du Cc: Cong Wang Cc: Jakub Kicinski Cc: David Laight Cc: Christian Brauner --- drivers/net/tun.c | 4 ++++ net/socket.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 84f832806313..8ec5977d2f34 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3003,9 +3003,13 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, } else if (cmd == TUNSETQUEUE) { return tun_set_queue(file, &ifr); } else if (cmd == SIOCGSKNS) { +#ifdef CONFIG_NET_NS if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; return open_related_ns(&net->ns, get_net_ns); +#else + return -EOPNOTSUPP; +#endif } rtnl_lock(); diff --git a/net/socket.c b/net/socket.c index 27e3e7d53f8e..bc644030d2e8 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1149,11 +1149,15 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) mutex_unlock(&vlan_ioctl_mutex); break; case SIOCGSKNS: +#ifdef CONFIG_NET_NS err = -EPERM; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) break; err = open_related_ns(&net->ns, get_net_ns); +#else + err = -EOPNOTSUPP; +#endif break; case SIOCGSTAMP_OLD: case SIOCGSTAMPNS_OLD: