Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753397Ab3CGJph (ORCPT ); Thu, 7 Mar 2013 04:45:37 -0500 Received: from mail-pa0-f42.google.com ([209.85.220.42]:49374 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184Ab3CGJpf (ORCPT ); Thu, 7 Mar 2013 04:45:35 -0500 Message-ID: <1362649361.14735.5.camel@beeld> Subject: [PATCH] nsproxy: Fix ->nsproxy counting problem in copy_namespace. From: Rakib Mullick To: linux-kernel@vger.kernel.org Cc: "Eric W. Biederman" , Serge Hallyn , Andrew Morton Date: Thu, 07 Mar 2013 15:42:41 +0600 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.1 (3.4.1-2.fc17) Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1536 Lines: 44 >From cd41495e25cf2641ffe9e01a40d3d221a46b08be Mon Sep 17 00:00:00 2001 From: Rakib Mullick Date: Thu, 7 Mar 2013 14:52:20 +0600 Subject: [PATCH] nsproxy: Fix ->nsproxy counting problem in copy_namespace. In copy_namespace(), get_nsproxy() (which increments nsproxy->count) is called before checking namespace related flags. Therefore, task's nsproxy->count could have improper value, which could lead to calling free_nsproxy unnecessarily. Also, incrementing nsproxy->count is an atomic operation (which is expensive than normal increment operation), so before doing it - it's better we make sure namespace related flags are set. Signed-off-by: Rakib Mullick --- kernel/nsproxy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index afc0456..de36209 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -130,12 +130,12 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) if (!old_ns) return 0; - get_nsproxy(old_ns); - if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWPID | CLONE_NEWNET))) return 0; + get_nsproxy(old_ns); + if (!ns_capable(user_ns, CAP_SYS_ADMIN)) { err = -EPERM; goto out; -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/