From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42222 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751338AbdGRQQV (ORCPT ); Tue, 18 Jul 2017 12:16:21 -0400 Subject: Patch "Drivers: hv: vmbus: Close timing hole that can corrupt per-cpu page" has been added to the 4.11-stable tree To: mikelley@microsoft.com, gregkh@linuxfoundation.org, kys@microsoft.com Cc: , From: Date: Tue, 18 Jul 2017 18:16:11 +0200 Message-ID: <1500394571214131@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled Drivers: hv: vmbus: Close timing hole that can corrupt per-cpu page to the 4.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drivers-hv-vmbus-close-timing-hole-that-can-corrupt-per-cpu-page.patch and it can be found in the queue-4.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 13b9abfc92be7c4454bff912021b9f835dea6e15 Mon Sep 17 00:00:00 2001 From: Michael Kelley Date: Thu, 18 May 2017 10:46:07 -0700 Subject: Drivers: hv: vmbus: Close timing hole that can corrupt per-cpu page From: Michael Kelley commit 13b9abfc92be7c4454bff912021b9f835dea6e15 upstream. Extend the disabling of preemption to include the hypercall so that another thread can't get the CPU and corrupt the per-cpu page used for hypercall arguments. Signed-off-by: Michael Kelley Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -82,10 +82,15 @@ int hv_post_message(union hv_connection_ aligned_msg->message_type = message_type; aligned_msg->payload_size = payload_size; memcpy((void *)aligned_msg->payload, payload, payload_size); - put_cpu_ptr(hv_cpu); status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL); + /* Preemption must remain disabled until after the hypercall + * so some other thread can't get scheduled onto this cpu and + * corrupt the per-cpu post_msg_page + */ + put_cpu_ptr(hv_cpu); + return status & 0xFFFF; } Patches currently in stable-queue which might be from mikelley@microsoft.com are queue-4.11/drivers-hv-vmbus-close-timing-hole-that-can-corrupt-per-cpu-page.patch