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=-15.7 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,URIBL_BLOCKED,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 08BAAC2B9F4 for ; Sun, 20 Jun 2021 02:52:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2508611ED for ; Sun, 20 Jun 2021 02:52:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229851AbhFTCzC (ORCPT ); Sat, 19 Jun 2021 22:55:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229591AbhFTCzB (ORCPT ); Sat, 19 Jun 2021 22:55:01 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCD74C061574; Sat, 19 Jun 2021 19:52:48 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id v12so6666032plo.10; Sat, 19 Jun 2021 19:52:48 -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=4gE1UXUdRdz6eukgpcCvaOI9F8pK5g/stV5KV8OaApU=; b=TZQTIJ1ytVDHkDfWlg4L3uBz1a7EY5wQemSUrR2I5IeKC4X5hesgbUSWZdl4rcn43R db5IF3TU0yFnGMxBtpYjqxRO75yQ8g1aIs5AkdHV/CF9cgtVd/r5mgIe9Dv2rhEf94LD QKDjQS+hQ+wEqO0C74reQrmVSE65fcgQjPZo9Y5NUamcT9SOhl3jZmyZqwRW+ICTxYlB Cl7+P2YOWGYevW9sg+n1lBKYlNJsh13bN80yHAZdFoQWasjagkJhmNkPsHcTrJfSGtp1 05eTWkzJ1N7j7/hCue1w1rDXmogtSyNr7EniVFJJj5x6XfwBW4Lu+Qac/ng13Fi7V/m8 F4Bw== 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=4gE1UXUdRdz6eukgpcCvaOI9F8pK5g/stV5KV8OaApU=; b=soYNd+j0sdj1HPezx2KNXArSFlnXcFxyQfQ/Q04GiuE+9BjK2MqKYM7mrZoyr+E3v6 kDkKl2C+q8ezq+PLR0/H+9YwKMiIOEfbNGunimzd4dyC4Uc5+kxR9ZHdIcx1uEq52zRF L4TVnFBkObK5pDcoLc5WVnmQdxqg0BycpWdcvCxSMlT+5iFS3hnmXx/sGnRBR3Sn1/CM xF7I1Z2c2ubCGDZZ3Bim+goOZ+MvR9w9CJPD2CxWK5GqgQZcjtrbqXZXy8z+mN91Y20c qBPersZ4sawzRxU3ixqio3UzDgrTix7wu0S2Agu8EKsbgiMfLbHEIoYo/wrVGTq5FKtK mimQ== X-Gm-Message-State: AOAM533nC1u0PjGUrxr9As7DLu1QfvelYpJC9ShLRxj2yCnFErMu7JyU dsPvvj7y6lFUVAvoGMRUgYg= X-Google-Smtp-Source: ABdhPJxkc9vmvlV1CJKEN/lgkpGzYDW3T3HnXwQOf5gmy85CQ8Utm9IrFPkZW23YLSd5U/I/p8W+3Q== X-Received: by 2002:a17:90b:3142:: with SMTP id ip2mr29572306pjb.63.1624157568193; Sat, 19 Jun 2021 19:52:48 -0700 (PDT) Received: from WRT-WX9.. ([141.164.41.4]) by smtp.gmail.com with ESMTPSA id p11sm11775548pfo.126.2021.06.19.19.52.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Jun 2021 19:52:47 -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: [RESEND PATCH v2] nsfs: warn if ns->ops is not provided Date: Sun, 20 Jun 2021 10:52:38 +0800 Message-Id: <20210620025238.2820-1-changbin.du@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org We should not create inode for disabled namespace. A disabled namespace sets its ns->ops to NULL. Kernel could panic if we try to create a inode for such namespace. Here is an example oops in socket ioctl cmd SIOCGSKNS when NET_NS is disabled. Kernel panicked 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 So let's print a warning for such unexpected request which to create the nsfs inode. The issue in networking will be fixed in another change. Signed-off-by: Changbin Du Cc: Cong Wang Cc: Jakub Kicinski Cc: David Laight Cc: Christian Brauner --- fs/nsfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/nsfs.c b/fs/nsfs.c index 800c1d0eb0d0..a132827bddd5 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -62,6 +62,9 @@ static int __ns_get_path(struct path *path, struct ns_common *ns) struct inode *inode; unsigned long d; + if (WARN_ON_ONCE(!ns->ops)) + return -EINVAL; + rcu_read_lock(); d = atomic_long_read(&ns->stashed); if (!d) -- 2.30.2