From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: David Vrabel , Konrad Rzeszutek Wilk , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 237/305] xen-scsiback: safely copy requests Date: Fri, 15 Jan 2016 16:00:51 -0800 Message-Id: <1452902519-2754-238-git-send-email-kamal@canonical.com> In-Reply-To: <1452902519-2754-1-git-send-email-kamal@canonical.com> References: <1452902519-2754-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: David Vrabel commit be69746ec12f35b484707da505c6c76ff06f97dc upstream. The copy of the ring request was lacking a following barrier(), potentially allowing the compiler to optimize the copy away. Use RING_COPY_REQUEST() to ensure the request is copied to local memory. This is part of XSA155. Reviewed-by: Juergen Gross Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Kamal Mostafa --- drivers/xen/xen-scsiback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c index 9eeefd7..2af9aa8 100644 --- a/drivers/xen/xen-scsiback.c +++ b/drivers/xen/xen-scsiback.c @@ -727,7 +727,7 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info) if (!pending_req) return 1; - ring_req = *RING_GET_REQUEST(ring, rc); + RING_COPY_REQUEST(ring, rc, &ring_req); ring->req_cons = ++rc; err = prepare_pending_reqs(info, &ring_req, pending_req); -- 1.9.1