From 89739c14c72e5c1626a5cd5e09cbb2efeaadb6d8 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Mon, 16 Nov 2015 18:02:32 +0000 Subject: [PATCH 6/7] xen-scsiback: safely copy requests 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. CC: stable@vger.kernel.org Reviewed-by: Juergen Gross Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk --- 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 43bcae8..ad4eb10 100644 --- a/drivers/xen/xen-scsiback.c +++ b/drivers/xen/xen-scsiback.c @@ -726,7 +726,7 @@ 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); -- 2.1.0