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