From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162531AbdEWVPv (ORCPT ); Tue, 23 May 2017 17:15:51 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56050 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1034008AbdEWVAq (ORCPT ); Tue, 23 May 2017 17:00:46 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vovo Yang , Guenter Roeck , "Eric W. Biederman" Subject: [PATCH 3.18 17/59] pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes Date: Tue, 23 May 2017 22:09:45 +0200 Message-Id: <20170523200850.418448505@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200849.241966497@linuxfoundation.org> References: <20170523200849.241966497@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric W. Biederman commit b9a985db98961ae1ba0be169f19df1c567e4ffe0 upstream. The code can potentially sleep for an indefinite amount of time in zap_pid_ns_processes triggering the hung task timeout, and increasing the system average. This is undesirable. Sleep with a task state of TASK_INTERRUPTIBLE instead of TASK_UNINTERRUPTIBLE to remove these undesirable side effects. Apparently under heavy load this has been allowing Chrome to trigger the hung time task timeout error and cause ChromeOS to reboot. Reported-by: Vovo Yang Reported-by: Guenter Roeck Tested-by: Guenter Roeck Fixes: 6347e9009104 ("pidns: guarantee that the pidns init will be the last pidns process reaped") Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- kernel/pid_namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -234,7 +234,7 @@ void zap_pid_ns_processes(struct pid_nam * Make sure they all go away, see free_pid(). */ for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); + set_current_state(TASK_INTERRUPTIBLE); if (pid_ns->nr_hashed == init_pids) break; schedule();