Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758460AbaDVVSt (ORCPT ); Tue, 22 Apr 2014 17:18:49 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36200 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757383AbaDVUP2 (ORCPT ); Tue, 22 Apr 2014 16:15:28 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Oleg Nesterov , ebiederm@xmission.com, Linus Torvalds , Kamal Mostafa Subject: [PATCH 3.8 115/133] pid_namespace: pidns_get() should check task_active_pid_ns() != NULL Date: Tue, 22 Apr 2014 13:14:13 -0700 Message-Id: <1398197671-12786-116-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1398197671-12786-1-git-send-email-kamal@canonical.com> References: <1398197671-12786-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.22 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit d23082257d83e4bc89727d5aedee197e907999d2 upstream. pidns_get()->get_pid_ns() can hit ns == NULL. This task_struct can't go away, but task_active_pid_ns(task) is NULL if release_task(task) was already called. Alternatively we could change get_pid_ns(ns) to check ns != NULL, but it seems that other callers are fine. Signed-off-by: Oleg Nesterov Cc: Eric W. Biederman ebiederm@xmission.com> Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- kernel/pid_namespace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index bea15bd..7d40b94 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -314,7 +314,9 @@ static void *pidns_get(struct task_struct *task) struct pid_namespace *ns; rcu_read_lock(); - ns = get_pid_ns(task_active_pid_ns(task)); + ns = task_active_pid_ns(task); + if (ns) + get_pid_ns(ns); rcu_read_unlock(); return ns; -- 1.9.1 -- 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/