From 46edd2ae852e19ee3a1b473be949691c6ce5694d Mon Sep 17 00:00:00 2001 From: Alex Williamson 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 RH-Acked-by: Bandan Das RH-Acked-by: Laszlo Ersek 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 Reviewed-by: Laszlo Ersek Signed-off-by: Alex Williamson --- 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 --- 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