| Message ID | 20150416180053.3224.5870.stgit@gimli.home |
|---|---|
| State | New |
| Headers | show |
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 6b80539..d387fbd 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2394,7 +2394,7 @@ static void vfio_map_bar(VFIOPCIDevice *vdev, int nr) if (vdev->msix && vdev->msix->table_bar == nr) { uint64_t start; - start = HOST_PAGE_ALIGN(vdev->msix->table_offset + + start = HOST_PAGE_ALIGN((uint64_t)vdev->msix->table_offset + (vdev->msix->entries * PCI_MSIX_ENTRY_SIZE)); size = start < bar->region.size ? bar->region.size - start : 0;
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> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- hw/vfio/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)