From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756418AbdKOFrN (ORCPT ); Wed, 15 Nov 2017 00:47:13 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:25706 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791AbdKOFrI (ORCPT ); Wed, 15 Nov 2017 00:47:08 -0500 From: Vasily Averin Subject: [PATCH] memory leaks triggered by perf --namespace To: linux-kernel@vger.kernel.org, Hari Bathini , Alexander Shishkin Cc: Namhyung Kim , Jiri Olsa , Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra Message-ID: Date: Wed, 15 Nov 2017 08:47:02 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org perf with --namespace key leaks various memory objects including namespaces # uname -r 4.14.0+ # perf record -q --namespace unshare -n -U -p --fork true # grep namespace /proc/slabinfo pid_namespace 1 12 2568 12 8 user_namespace 1 39 824 39 8 net_namespace 1 5 6272 5 8 This happen because perf_fill_ns_link_info() struct patch ns_path: during initialization ns_path incremented counters on related mnt and dentry, but without lost path_put nobody decremented them back. Leaked dentry is name of related namespace, and its leak does not allow to free unused namespace. Fixes: commit e422267322cd ("perf: Add PERF_RECORD_NAMESPACES to include namespaces related info") Signed-off-by: Vasily Averin --- kernel/events/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 10cdb9c..ab5ac84 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6756,6 +6756,7 @@ static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, ns_inode = ns_path.dentry->d_inode; ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev); ns_link_info->ino = ns_inode->i_ino; + path_put(&ns_path); } } -- 2.7.4