From 46edd2ae852e19ee3a1b473be949691c6ce5694d Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@redhat.com>
Date: Fri, 1 May 2015 18:09:33 +0200
Subject: [PATCH 09/14] vfio-pci: Further fix BAR size overflow
Message-id: <20150501180733.31334.63326.stgit@gimli.home>
Patchwork-id: 64972
O-Subject: [RHEL7.2 qemu-kvm PATCH 9/8] vfio-pci: Further fix BAR size overflow
Bugzilla: 1181267
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Bandan Das <bsd@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
Bugzilla: 1181267
Upstream: 07ceaf98800519ef9c5dc893af00f1fe1f9144e4
In an analysis by Laszlo, the resulting type of our calculation for
the end of the MSI-X table, and thus the start of memory after the
table, is uint32_t. We're therefore not correctly preventing the
corner case overflow that we intended to fix here where a BAR >=4G
could place the MSI-X table to end exactly at the 4G boundary. The
MSI-X table offset is defined by the hardware spec to 32bits, so we
simply use a cast rather than changing data structure types. This
scenario is purely theoretically, typically the MSI-X table is located
at the front of the BAR.
Reported-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
Brew for series including 9 & 10:
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=9082147
hw/misc/vfio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
hw/misc/vfio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index cbc9d8a..e6f96db 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -2634,7 +2634,7 @@ static void vfio_map_bar(VFIODevice *vdev, int nr)
if (vdev->msix && vdev->msix->table_bar == nr) {
uint64_t start;
- start = TARGET_PAGE_ALIGN(vdev->msix->table_offset +
+ start = TARGET_PAGE_ALIGN((uint64_t)vdev->msix->table_offset +
(vdev->msix->entries * PCI_MSIX_ENTRY_SIZE));
size = start < bar->size ? bar->size - start : 0;
--
1.8.3.1