From patchwork Fri Apr 3 01:56:18 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 6153251 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id EB9DCBF4A7 for ; Fri, 3 Apr 2015 02:01:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 187752035E for ; Fri, 3 Apr 2015 02:01:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6C2A203B0 for ; Fri, 3 Apr 2015 02:01:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753376AbbDCCBs (ORCPT ); Thu, 2 Apr 2015 22:01:48 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:56121 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753264AbbDCCBn (ORCPT ); Thu, 2 Apr 2015 22:01:43 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1YdqvW-0002CF-Rn; Thu, 02 Apr 2015 20:01:42 -0600 Received: from 70-59-163-10.omah.qwest.net ([70.59.163.10] helo=x220.int.ebiederm.org) by in01.mta.xmission.com with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.82) (envelope-from ) id 1Ydquj-0003Lp-1A; Thu, 02 Apr 2015 20:00:53 -0600 From: "Eric W. Biederman" To: Linux Containers Cc: , "Serge E. Hallyn" , Andy Lutomirski , Richard Weinberger , Andrey Vagin , Al Viro , Jann Horn , Willy Tarreau , Omar Sandoval Date: Thu, 2 Apr 2015 20:56:18 -0500 Message-Id: <1428026183-14879-14-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 2.2.1 In-Reply-To: <87a8yqou41.fsf_-_@x220.int.ebiederm.org> References: <87a8yqou41.fsf_-_@x220.int.ebiederm.org> X-XM-AID: U2FsdGVkX185FZw0T8BlYJcNTRrMUKuDhzskMMMUssk= X-SA-Exim-Connect-IP: 70.59.163.10 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-DCC: XMission; sa06 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;Linux Containers X-Spam-Relay-Country: X-Spam-Timing: total 383 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 3.6 (0.9%), b_tie_ro: 2.6 (0.7%), parse: 0.84 (0.2%), extract_message_metadata: 13 (3.5%), get_uri_detail_list: 1.17 (0.3%), tests_pri_-1000: 6 (1.5%), tests_pri_-950: 1.26 (0.3%), tests_pri_-900: 1.06 (0.3%), tests_pri_-400: 18 (4.6%), check_bayes: 16 (4.3%), b_tokenize: 4.1 (1.1%), b_tok_get_all: 6 (1.6%), b_comp_prob: 1.36 (0.4%), b_tok_touch_all: 2.7 (0.7%), b_finish: 0.74 (0.2%), tests_pri_0: 329 (85.8%), tests_pri_500: 8 (2.1%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH review 14/19] mnt: Fix the error check in __detach_mounts X-SA-Exim-Version: 4.2.1 (built Wed, 24 Sep 2014 11:00:52 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP lookup_mountpoint can return either NULL or an error value. Update the test in __detach_mounts to test for an error value to avoid pathological cases causing a NULL pointer dereferences. The callers of __detach_mounts should prevent it from ever being called on an unlinked dentry but don't take any chances. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 1894d1878dbc..e8f7f8c58c3c 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1516,7 +1516,7 @@ void __detach_mounts(struct dentry *dentry) namespace_lock(); mp = lookup_mountpoint(dentry); - if (!mp) + if (IS_ERR_OR_NULL(mp)) goto out_unlock; lock_mount_hash();