From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45480 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729531AbeICVpU (ORCPT ); Mon, 3 Sep 2018 17:45:20 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Davidlohr Bueso , Manfred Spraul , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.14 056/165] ipc/sem.c: prevent queue.status tearing in semop Date: Mon, 3 Sep 2018 18:55:42 +0200 Message-Id: <20180903165657.941791272@linuxfoundation.org> In-Reply-To: <20180903165655.003605184@linuxfoundation.org> References: <20180903165655.003605184@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Davidlohr Bueso [ Upstream commit f075faa300acc4f6301e348acde0a4580ed5f77c ] In order for load/store tearing prevention to work, _all_ accesses to the variable in question need to be done around READ and WRITE_ONCE() macros. Ensure everyone does so for q->status variable for semtimedop(). Link: http://lkml.kernel.org/r/20180717052654.676-1-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Cc: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- ipc/sem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/ipc/sem.c +++ b/ipc/sem.c @@ -2041,7 +2041,7 @@ static long do_semtimedop(int semid, str } do { - queue.status = -EINTR; + WRITE_ONCE(queue.status, -EINTR); queue.sleeper = current; __set_current_state(TASK_INTERRUPTIBLE);