From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752103Ab1IZPSq (ORCPT ); Mon, 26 Sep 2011 11:18:46 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:48425 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751567Ab1IZPSo (ORCPT ); Mon, 26 Sep 2011 11:18:44 -0400 Date: Mon, 26 Sep 2011 10:18:29 -0500 From: Serge Hallyn To: Alan Stern Cc: "Serge E. Hallyn" , Greg KH , Oleg Nesterov , lkml , richard@nod.at, Andrew Morton , "Eric W. Biederman" , Tejun Heo , linux-usb@vger.kernel.org, "Serge E. Hallyn" Subject: [PATCH] pid_ns: ensure pid is not freed during kill_pid_info_as_uid Message-ID: <20110926151829.GA5190@peqn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alan Stern points out that after spin_unlock(&ps->lock) there is no guarantee that ps->pid won't be freed. Since kill_pid_info_as_uid() is called after the spin_unlock(), the pid passed to it must be pinned. Signed-off-by: Serge Hallyn --- drivers/usb/core/devio.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 37518df..eea53eb 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -407,7 +407,7 @@ static void async_completed(struct urb *urb) sinfo.si_errno = as->status; sinfo.si_code = SI_ASYNCIO; sinfo.si_addr = as->userurb; - pid = as->pid; + pid = get_pid(as->pid); uid = as->uid; euid = as->euid; secid = as->secid; @@ -422,9 +422,11 @@ static void async_completed(struct urb *urb) cancel_bulk_urbs(ps, as->bulk_addr); spin_unlock(&ps->lock); - if (signr) + if (signr) { kill_pid_info_as_uid(sinfo.si_signo, &sinfo, pid, uid, euid, secid); + put_pid(pid); + } wake_up(&ps->wait); } -- 1.7.0.4