1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 9098d880c476..d22f4b5bbc04 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -298,12 +298,16 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                         map_irq.entry_nr = nvec;
                 } else if (type == PCI_CAP_ID_MSIX) {
                         int pos;
+                        unsigned long flags;
                         u32 table_offset, bir;
 
                         pos = dev->msix_cap;
                         pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
                                               &table_offset);
                         bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+                        flags = pci_resource_flags(dev, bir);
+                        if (!flags || (flags & IORESOURCE_UNSET))
+                                return -EINVAL;
 
                         map_irq.table_base = pci_resource_start(dev, bir);
                         map_irq.entry_nr = msidesc->msi_attrib.entry_nr;