Commit be69746e authored Nov 16, 2015 by David Vrabel Committed by Konrad Rzeszutek Wilk Dec 18, 2015

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 <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

parent 18779149

drivers/xen/xen-scsiback.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);